My 512GB iPhone requires me to turn on Optimize Photos. I’d rather have everything on the iPhone. It’s quicker to look through photos and play videos and especially convenient on flights. I take 4K video on trips. So the 1TB will be a welcome upgrade for me. I’m not worried about how quickly it ships. I’m Willing to wait if needed.
Sounds like me, I have to have everything on my iPhone, so a 1TB option is what I've been waiting for, I hoped 2020's 12 Pro Max would have it, but now that they added pro motion, I think it will have been worth the wait for the 1TB option.
I don't even have 1TB on my iMac. On iPhone? Fuhgeddaboudit!
Plus when you trade in your old iPhone with Apple, they don't take storage into account; they offer same money for 4GB iPhone or 4TB iPhone.
P.S. Who else had the original iPhone with 4GB of storage? I did, and I thought it was more than enough at the time 😂 How times have changed.
I specifically got a 1TB MacBook Pro in hopes of them releasing a 1TB iPhone.
As for the 4GB iPhone, lol, I didn't get my first iPhone until a few months before the 6S+, I had no clue when preorders happened, I was finally able to get my credit good enough for AT&T to do a 2yr plan, so I paid what the 2yr plan was for the 6+, 64GB, even that felt like not enough for me. So the 1TB is a nice and welcomed addition.
Apple has been selling iPhones for decades, they know roughly how much each storage version is going to sell. So they will make less 1TB version
I hope they make enough for day 1 for those who want them, the fact that they decided that the Pro/Pro Max's needed 4 storage options is great, as not everyone wants 128, 256, 512 or 1TB, also the fact they are starting all iPhone 13 models at 128GB is great, I think with the way apps are so damn much bigger file size, photos, videos, etc.. you need more than the normal 64GB that they used to offer.
This is very simple, if you want 1TB, get it, if you do not want it then DO NOT get it, but 1TB on an iPhone is NOT overkill for those who want or need it, if all you need is 128GB then good for you, some of us want or need more. The smartphone is the one device that some of us carry everywhere we go whereas my iPad Pro mostly stays at home, so I do not mind my iPad and my laptop having less storage, as long as I have a external SSD to back my stuff up to along with iCloud.
Gotta love the variety all of us techies, some need/want more and some don't and good for them.

If you do not want or need more please do not speak for the rest of us.
Thank you, for some who feel it's a needed addition, like myself, it's not overkill. And yes of the 1 device I carry the most between my iPhone, iPad, & MacBook, it's my iPhone, and at 6.5, well now for me it'll be 6.7 inch screen, it's big enough for me to get through the day, just bring a powerbank or external battery, and you're good to go IMO, I have one that you can have multiple things charging, like I can have my iPhone, my iPad, my Switch all charging.