One of the most unfortunate things in the US is locked bootloaders. AT&T has even started whitelisting phones for Wifi Calling and VoLTE. And with 3g shutting down, it means international phone variants won't work at all on the network, regardless of the underlying band support. Many companies, including Samsung don't allow you to unlock your bootloader to root your phone even if you bought it outright. I found that midrange phones are now the best option if you want things like AOSP. The only true flagship left, that I know of, with a headphone jack and sd card and good rooting support is the Sony Xperia phones.
We'll always have the versions of AOSP Google has released, but they're not forced to do so in the future. And I'm not sure anyone else is interested in maintaining it.
Google only releases AOSP for Pixel devices, for most devices you need to rely on (and trust) some dude on a forum and it might not have 100% compatibility.
Isn't Fuchsia google's attempt to move phone off open systems, and onto all-google-no-license code? If it becomes a big thing, then only increasingly obsolete open-systems for us :(
I'm with you, but we'll always have AOSP. And the cellphone market is now segmented enough that we'll probably also always have rootable phones.