> There is the valid argument, of sealing it in, for water protection.

There is an argument, perhaps, I don't know about a "valid" one.

The difference between "the battery can be swapped with a screw driver" and "the battery can be swapped by a repair shop in 15 minutes" isn't really that large, so if it can make devices more compact, sure, why not?

Batteries that outright can't be replaced are something else entirely. Maybe some consumers are willing to make the trade, but it's environmentally irresponsible. The Airpods in particular really piss me off given all of Apple's environmental messaging.

That is incorrect. The Samsung Galaxy S5 had a removable battery and headphone jack and was still waterproof. It was a $550 phone and was a flagship with the latest hardware/performance stuff, so clearly this was practical from a cost/manufacturing standpoint. Waterproofing is not a valid reason against having removable batteries or ports.