A) Pls provide citation of your claim
Go check MacTracker. A 2006 Core Duo Mac stopped being able to run the latest Mac OS X release with Lion in 2011; you could still get security updates for Snow Leopard, its final release through 2013. That's 5 years with a 2 year buffer for security update support. Compare that with a 2012 model (Ivy Bridge/3rd Generation Intel Core i series processor) Mac, which was able to run the latest version of macOS up until twelve days ago. That's 8 years with a 2 year buffer for security update support.
Go do the research for yourself.
B) WWDC 2005 keynote of Steve Jobs claimed a 2 year transition just like WWDC 2020 keynote of Tim Cook. 2005 has Apple having a market cap of $75 billion while 2020 having a market cap of $2 trillion. With more resources than AMD, Intel and Nvidia combined why can't Apple, who produced iPads and iPhones in the same quantity as the global PC market of 2019 need to take their time?
Because the chips are not ready yet. If they were, Apple would've fully replaced the entire Mac mini line and not only the low-end Intel model. Also, the M1 Mac mini would be a no-compromises upgrade (in the way that the M1 2-port 13" MacBook Pro was over its Coffee Lake predecessor) and not one where the maximum RAM is one fourth what it is on the Intel model and where there's half the number of Thunderbolt ports. Clearly the M1 has limitations because it's the best Apple can do right now.
Market caps don't mean anything. Apple doesn't need to throw more money at this; the M1 Macs are a critical success and it doesn't hurt Apple to do things exactly as they currently are doing things. Steve Jobs was a master salesman; under-promise and over-deliver. The Intel lineup was fine for the Mac to move at the exact time that it did and the Core Duo was perfect for all but the Mac Pro and Xserve, which waited for the Core 2-based Xeons to move. Once A15, and all associated advances become closer to releasing, you'll see higher-end Macs make the jump. Odds are decent that the Mac Pro's eventual Apple Silicon SoC will need even more time in the oven.
Who will buy any Intel Mac that is slower than any M1 Mac at a fraction fo the cost? If they keep to the two years declared they will suffer the Osborne Effect. Who would buy a $6,000 Mac Pro when $700 Mac mini can trample it?
People who still need x86. Not everything runs smoothly in Rosetta 2. And just because you don't need the things a Mac Pro or a 16" MacBook Pro customer might need doesn't mean that those customers don't need their installed software to be perfectly stable until it makes the jump to Apple Silicon.
There are plenty of people out there who will still be buying Intel Macs throughout this transition for that reason. Furthermore, it's not like an Intel Mac is a bad computer just because Apple Silicon is out. Maybe it's not the most practical decision, especially if everything one would do with their Mac is either Apple Silicon native or runs just as well in Rosetta 2. But that's not all people, especially on the high end.
Apple is going to move the machines over as fast as they can. And that length of time seems like it will be two years.
Apple makes iPhone chips in greater quantities than Intel and AMD combined on a 5nm process that neither x86 chip makers use.
That doesn't mean that they have chips that can feature-for-feature replace every Intel Mac. They have single-core performance down, but they don't have GPUs that beat out the current discrete graphics on the 16" MacBook Pro, 27" iMac, iMac Pro, or Mac Pro yet. That crap takes time to engineer. They also can't break 16GB of RAM or provide more than 2 Thunderbolt ports. That's critical. That's why this transition will take longer than the Intel one did. And really, those are factors that are specific to this transition (and wouldn't ever stop the previous transition due to not being applicable).
M1 is designed for less than 15W TDP. A future higher-end Apple Silicon chip designed for more than 15W TDP will come out for the iMac, MacBook Pro 16", and four TB4/USB4 port MacBook Pro 13"and Mac mini between January-April 2021.
You have different wattages on the M1 chips. That's why the M1 Air and M1 2-port 13" MacBook Pro have different chargers and why the latter operates with greater sustained performance than the former and why the M1 Mac mini, theoretically beats out both of them. Go take a look at Apple's M1 performance per watt graph. The performance scales as the wattage increases.
C) Intel and AMD will not be relevant on macOS as early as 2024.
Not for new Macs. But certainly for Intel Macs as far as driver support in new releases is concerned.
As to Intel & AMD being relevant on Windows is another matter. Apple's success with ARM may accelerate Microsoft giving equal resources to support x86 and ARM on Windows.
Microsoft isn't a chipmaker that designs its own SoCs and solely for its own products the way Apple does. Furthermore, for Windows 10 for ARM64 to succeed, Microsoft can't be the only company making devices for it. The other OEMs have to buy in as well. Microsoft could decide to make SoCs and license them to the other OEMs. That's a possibility. But for that to happen quickly would entail a ton of things happening.
Android chips do not have the performance per Watt of Apple chips but they do not have to be as they're superior to Intel and even perhaps AMD chips.
No, Android CPUs have good performance per watt as well. That's a byproduct of the ARM64 architecture. Android may not use said performance efficiently, but those SoCs are also beasts.
Imagine, by the year 2024 buying a Windows ultrabook powered by a Qualcomm, Samsung, Nvidia, Mediatek or Huawei chip that has better battery than any Intel or AMD chip. Laptops make up over 80% of all shipped personal computers. Desktops less than 20%.
They already exist and they do not perform well. Though a lot of that is the lack of decent x86 binary translation in Windows 10 for ARM64. Otherwise, the performance compared to Apple Silicon is leaving much to be desired. But that's because Apple has heavily customized their implentation of ARM64. Qualcomm and Samsung would need to do something similar and, even then, they won't have going for them what Apple does in that Apple as a chipmaker is only designing for Apple and only for Apple's operating system. That's not something that the others will remedy in four years.
The PC market is a fraction of the smartphone market so it is easy to takeover from incumbents.
Apple has SoCs suitable for all their Macs were completed months ago. They're just doing prototyping and testing so nothing launched between November to June will fail.
My turn to ask you for a citation here. There's no indication that Apple is ready with anything other than an SoC suitable for an entry level iMac at this point. Otherwise, the 2 Thunderbolt port limit and 16GB of RAM cap on the Mac mini (and continued sale of the higher-end Intel Mac mini models as well as the Intel 4-port 13" MacBook Pro) would lead me to believe that Apple still has a ways to go before they're ready to complete this transition.
Just like iPhone chips being designed today will be launched in iPhone/iPad by 2023 or 2024.
They don't spend three years in QA. That's not how that typically works.
