MacBook batteries have not been permanently glued in for quite some time. Replacement requires some disassembly but is perfectly doable for most techies.
Personally I prefer the current solution to adding weight and size.
I can’t remember my battery draining below 50% since I bought my M5 a while back. 10+ years ago I agree that the needs were different but these days needing swappable batteries seems like a very minor niche IMHO.
Sorry but why do we have to accept mediocre as acceptable these days? My old laptop had hot-swapable batteries.