I am always amazed how the red hat crowd managed to change the narrative around Ubuntu always starting their own thing instead of using something established.

Reality is that both snap (2014) and upstart (2006) came before flatpak (2015) and systemd (2010).

Now there might be valid reason why the later options are superior, however accusing Ubuntu to just do something different out of "fancy" seems quite unfair. They did develop a solution for things theat where widely regarded as problems (as evidenced by others later doing the same thing), where they failed (and there are multiple reasons IMO) is getting their solutions adopted by the wider community.