of course not. It might mean a slightly thicker phone, but with a bit of smart engineering and a regulatory incentive, I'd expect something quite elegant. Think about how your SIM tray pops out.
Replaceable batteries were great. I could keep phones going for years until Samsung started pumping out bloated software updates that slowed them down.
When we had replaceable batteries you could just buy a new one and performance issues would be corrected almost immediately. Apple was sneaky AF about this back in the day, throttling performance in an attempt to increase battery life, something that wouldn't be needed if you could easily swap out the battery every few years
That wouldn't be necessary. I had a metal phone with a replaceable battery (Motorola SLVR L7). It was more common for a cellphone to be made of plastic in the replaceable battery days because most phones were still far more utilitarian and thought of for talking, text messages, email if you had a data plan and of course Snake.
Lightweight and small was popular before large screens and smart features came along. One exception was the push-to-talk phones geared towards construction workers. Those suckers were chunky.
I remember using the Samsung Galaxy S2 which is ancient by today's standards, but one thing I remember distinctly was how super convenient it was to be able to pull the back off and switch out the battery, it reminded me of the simplicity of swapping batteries on a DSLR camera.
Some people mentioned that you'll drop your phone and the battery will just fly out. I don't remember ever having that happen and my S2 had a rough life.
The one part I feel is valid criticism is water resistance, manufacturers will have to actually work on their designs to get IP resistance now. As much as I love waterproof phones, I'd much rather be able to have a spare battery than think about what happens if I drop it in water