2. This entire article is about avoiding the Gnome private API. The only other alternative, the XDG/portal API, uses Pipewire. It's literally the only alternative even if you don't use Flatpak.
EDIT: Your "2018" link is also not showing the screencast portal API. And I am not blaming Wayland; I am blaming the distros who switch to it and as a consequence BROKE user programs.