That’s the point, it is so you don’t have to require any special tools that you have to purchase or rent, or having to deal with glue and all that crap.

But Why? If I switch the battery in my phone once after like 2-3 years, I can deal with that once just fine.

You think because it’s replaceable it can’t be compact and waterproof? Ever used a watch?

Ye, both watches and airtags have fairly small and round openings to seal up. Also airtags are only ip67, phones are ip68 which is a lot more difficult to achieve.

With a phone, you will then need to separate the battery from the rest of the phone, with some form of "compartment", that will use quite a lot of internal space and therefore make the packaging a lot worse, resulting in a smaller battery. You will then need some form of lid on the back that can be opened / closed again, and is still waterproof to ip68 or more. That requires a lot of pressure on quite complicated seals, with a copmlicated mechanism to hold the lid closed all around the edge. All of this will at least triple the cost of the phone case, which is already a very expensive point on the bom.

People complain phones are too expensive, but then they ask for uneccesary stuff like this...