Snap was here before flatpack, what should a company like Canonical do if they want to try something new? Use planted developers in GNOME or other projects to push projects as dependencies into all distributions?
If you do not like Canonical do not use their products, use other distro or BSD. Unity was a nice attempt to get a simple desktop that is not a slave of GNOME designers ideas, unfortunately it fails but I do not understand why people like you are against of options (only if the option is from Canonical) even if Canonical always tried to support all the DEs.