I also noticed in american media that people only open the zipper to take a piss, but not the button - maybe that’s the difference?

There’s the dirty part, and the neat part

That is what happens after the puncture, though. Doesn’t really change anything about what I said. But if that works for you, that’s good.

Meaning more surface area to hit something sharp. Yeah the larger area means lower pressure on the contact surface but I don’t think that’s the deciding factor in whether something punctures your tire. Best way to prevent punctures is tougher tires rather than larger ones. The lower pressure just helps with stuff like loose gravel or sand.

why would they be easier to maintain?

Sorry, no idea how to fix that, short of spending money. But if you ever end up considering doing that, I’d like to suggest buying music rather than paying for a subscription like YouTube premium or Spotify etc.