IIRC GNOME removed support for snaps from gnome-software so this was the only way forward.
According to git, gnome-software snap support still seems to be actively developed: https://gitlab.gnome.org/GNOME/gnome-software/-/commits/mast...
It's not true. GNOME Software still ships Snap plugin. It's Canonical that decided to fork gnome-software and provide it under different name without competition plugins enabled.
The graphical "gnome software" software installer was replaced in the default install by a snap-only fork named "Snap Store" with no support for Flatpak (see https://bugs.launchpad.net/snap-store/+bug/1871944). Were there some technical reasons for this move or was it a business decision to kneecap the other package format?