because these slop projects have a single dev. And if that dev happens to have a macbook, then that's that.
You can't have multi-platform support without external contributors, and of course you can't have external contributors when one dude is pumping out +2.5M LOC in a week.
Nope, this is all AI.
Sure you can, check https://github.com/gen2brain/iup-go , from single dev on Linux that for a long time used VMs for testing, macOS in VM, iOS simulator in that VM (painful), etc. OK, several months ago I bought some old iPhone first, then one month ago I bought Mac mini M1, just for testing. It needed years though, not few weekends, but it is doable.