When you say replaceable, do you mean repairable or swappable? Like, does it need to be done without tools (probably takes <1 minute) or would it take me 2 hours with a load of tools (no change from today) just that there's a legal requirement for them to be commercially available?

Fwiw, besides people that crack the screen I have not seen any of the failures you've mentioned. The only phone I saw someone replace, for reasons other than software support, was myself because the gnss chip was cooked after 3 years (would track me perfectly, like if I step to the right it would notice, but with an offset of hundreds of metres so I'm in another town). All other phones I've owned are still perfectly functioning (the oldest Android phone I have, 2012, has a more reliable battery than my daily driver!), I don't use any case or screen protector. They're just software-wise obsolete because no updates and developers require the newer android apis