It seems that canonical does best when they embrace the ecosystem and not try to replace it.
Canonical cannot be accused of NIH for Upstart, it was a widely adopted clean init system at the time and made many distro's boot times great again. Service configuration files were also very easy and clean.
Unity was a desktop environment that both was liked by many people and reused many components from Gnome, I don't really see a problem here.
A point could be made for Mir.
So it's wrong to say Canonical is guilty of NIH-syndrome with these two items, when their versions were out first.
Whether the tech is any good is another matter.
https://blogs.gnome.org/alexl/2018/06/20/flatpak-a-history/
According to https://en.wikipedia.org/wiki/Snappy_(package_manager), Snap was publicly revealed on 9 December 2014, whereas the design of xdg-app (FlatPak's old name) was already discussed publicly at GUADEC 2013.
https://www.superlectures.com/guadec2013/sandboxed-applicati...