Apple should have put its money/effort/resources into AMD. Apple's current problems:
1) Delay. They delayed a Mac Pro refresh for nearly 10 years. Specifically, they have ignored a large segment of potential and certain buyers.
More AMD in the Mac Pro would have meant even more delays. Folks are getting 20/20 hindsight here.
The selections for the Mac Pro would have needed to be made back in Spring/Summer 2017. AMD was doing better back then but didn't have the track record they have had over the last two years.
The hiccup of the Mac Pro having a 580X instead of perhaps a W5600X ( affodable Navi) card is indicative that AMD would not have meant better timing. Apple would have been doubling down on both CPU and GPU possible delays.
The 32 core Threadripper is coming months after the other 3 gen Threadrippers arrived because AMD couldn't get it out ( volume constrained). Apple wouldn't have been magically special on getting product.
Going AMD was a higher risk potential of being late than Intel back in 2017.
For the next Mac Pro ( and the 2020 Mac products that probably laid ground work for back in 2018 or early 2019 ) then that is different.
That 10 year span for the Mac Pro covered numerous years where they were not doing much work, but the lead time on this product isn't the 6-12 months lots of folks handwave about.
2) Shrinking the market segment. Apple decided that the Mac Pro wasn't for pro-sumers or enthusiasts anymore, but strictly for a narrow segment. Related closely to 3). This is actually huge.
That really isn't true. There is a difference between pro-sumers and enthusiasts and dogmatically dedicated to "box with slots" form factor. Pro-sumer and enthusiasts is larger than that. The number of Pro-sumers and enthusiasts buying laptops and all-in-one demonstratively show that.
AMD's Ryzen 4000 H APU product is putting what was recently "desktop" class CPU horepower in laptop. The MPB 16" basically outclasses most of the pre 2013 Mac Pros. The market has changed since 2008-2009 when iMacs only had close to an mobile CPU and GPU.
Apple has followed the market just as much as "unilaterally decided that .... " . The performance space that doesn't significantly overlap with the rest of the Mac line up has moved in the last 10 years. It is moved on other vendors too... The gap here is more so willingness to sell overlapping and more likely fratricide inducing products.
When I was going through graduate school and learning Graphic Design and the such, Apple made the Mac Pro affordable for my needs, although it was still expensive but palatable--I could work longer summer hours to get one by the end of summer. The Mac Pro is absolutely out of this realm for any college student.
Like holy cow couldn't possibly learn Graphic Design using a MBP 16" as tool now. *cough* . Using an iMac ( or iMac Pro ). Impossible? No. It is a
tool not a product form factor that is most conducive to learning.
Apple driving the base price higher on the Mac Pro is a long term somewhat risky move for Apple. They could high a pricing death spiral here where fewer folks buy because expensive and then price goes up because volume is lower (rise and repeat). However, that isn't solely Apple's move. Some customers have shifted too and that shift matters.
The bigger problem is Apple going back into Rip van Winkle mode on the Mac Pro for a long time. If Apple would cycle Mac Pro into "superseded" mode on a regular basis ( Mac Pro 2019 then Mac Pro 2021 then Mac Pro 2023 , etc. ) then the older versions would iterate down into the pricing slots closer to the older Mac Pro. Folks who "needed" a box with slot Mac Pro as a college student with limited budget would have something to grasp at if dogmatically adverse to other viable form factors.
The competitive market dynamics for major components in the current space the Mac Pro is targeting and going to sleep for 3-4 years would be bad even for the folks who do have the budget (and return on investment path) for the current Mac Pro. One factor in why Apple may not be quite aligned here is that they were doing a whole lot of nothing for a long time. So when they finally jumped back in they aren't necessarily aligned with what is going on.