It's official: Smartphones will need to have replaceable batteries by 2027
(www.androidauthority.com)
Some make the argument that batteries are already replaceable if you get the right tools, but it's not even a matter of making it possible.
I think it's more about making it so you aren't voiding your warranty and that the option is there.
Otherwise you replaced your battery and they decide they will never offer any support for your phone because you dared touch it.