this is like saying to only buy mac laptops, because an os is hard to install on your laptop. I guess that's why the corporate world and other people don't run a bunch of linux. because it's a "community project." redhad and ubunty are community projects. gotcha. they are. just like lineageos. supported by hundreds of paid developers and many huge companies.
installing an os on your phone is not simple. but it is harder than installing it on your laptop. and because installing it on a laptop is hard, people don't buy copies of windows and never have.
i am not glossing over complexity. but this is not complexity. anything apparently is complexity to you if it's not "buy small computer, and literally do nothing." yes, doing something is "complexity." opening a door requires keys. too complex.
us somewhat technical people, like this entire site and literally a third of the population, can follow xda directions. my gramma can watch a 15 minute youtube video and just click exactly what it says. the complexity is not complex.
as far as unlockable bootloaders, there are some. i can count on one hand, out of the hundreds of phones I can buy. if by many you mean 2%, sure. i guess that 2% means don't use 98% of phones. strange how apple is unlockable on 100% of their phones, yet that 2% is "worse."
When you play pretend with fake information, the only thing you are doing with the narrative is making yourself look like you're spreading narrative. this works for fox news watchers like yourself. not on a forum with a bunch of downvoting nerds.