Isn't it way way past time for smartphones to standardize the booting process the way PCs did back in the 80s? The old excuses of "we couldn't fit a generic kernel on our tiny built-in storage" rings hollow in these days of 16GB storage in the base model phones.

This isn't a hard problem. We solved it decades ago. There should be an "Smartphone Kernel" that gets updated like the Linux kernel with drivers for all variety of hardware that you can install on most every phone as is. Vendors could cut out drivers for hardware they aren't using, but a random person should be able to install a generic kernel and boot the phone. Android would be the userland installed on top of that kernel. But it seems like vendors are more interested in maintaining lock-in instead of simplifying their maintenance and update tasks.

For PCs there was a very clear reason. IBM was in the lead and everyone else wanted to have a clone that worked with the software for IBMs.

Right now Samsung seems to be number one in android phones. what benefit would they get from doing this? Making it easier to update their old products? They don’t care. All that does is make people buy fewer new phones.

Across all the vendors they could save time… but I kind of doubt they’ll ever do it. I don’t think that motivation is strong enough for them to change the way they do things.

This isn't that easy, you'd need support from SOC manufacturers, board manufacturers, also I believe ARM chips don't have feature enumeration as x86 chips do. Not to mention that your kernel would need to embed a whole lot of binary blobs since many things like modems are not open at all.

I'd like that as well of course but vendors don't seem very interested in cooperating with each other right now.

Frankly, I would prefer the ability to install what I want. Just because what is on the phone boots what I bought doesn't mean I want it on there. I think the objective of Project Treble was also to allow that to be much easier as well.

Having a locked bootloader means I an unable to truly install what I want.

Why not both?

To cut off anyone claiming this is a dichotomy - on LG phones, you already get both. They come locked, but if you root them, you get a warning saying it's rooted during every boot.

Yeah, Sony, Xiaomi and IIRC Google does that too. It's not both, it's either. Each individual customer of these companies gets to choose X or Y.