They exist, they just aren’t popular because most people don’t care.

Bootloader a are usually pretty easy to unlock, it's Safetynet that is the biggest problem these days. Though you can generally sandbox it a little bit with a custom ROM. If, however, you try to keep it stock and have it rooted with Magisk it can be a nightmare depending on the manufacturer.

Aside from maybe the headphone jack, those are all features that enthusiasts want but average consumers don't care about enough to compromise on size, waterproofing or price.

Smartphones depend so much on economies of scale, and a limited pool of cutting edge components, it would be hard to sustain a niche market just for enthusiasts.

Apple Mice have had right click for 14 years, and their trackpads have used two finger click in its place far longer than that. And before that, any two button mouse worked just fine in OS X from 2001 on (earlier if you ran the beta of OS X). So your information is anywhere from two decades to one and a half decades out of date. Well done.

I agree with you and the OP of this thread. I don't want to support a company with a walled garden approach and they over complicate things to be unique

"We stopped including a charger in the box to help the environment"

Actually this means more boxes are being created in total and this is worse for the environment.

How so? That thought only works if you think they still manufacture the same amount of chargers and package them. Which would be pretty dumb given that they aren’t guaranteed a sell. Also, who doesn’t have a bunch of different chargers already?

I went with the Motorola G Stylus 5g. It's not perfect, but it does have an SD slot, a headphone jack, FM radio, an easily unlocked bootloader, and a built-in stylus I didn't expect to care about but which I have grown weirdly dependent on. I just wish it had a removable battery.