Mir came about because the people behind Wayland were fucking around for years without making progress.

This implies the motivation was either one or another. It's both: Canonical saw there was room to push for Mir, because the Wayland project was stagnant.

Now that Wayland has actually matured, Mir is a Wayland compositor.

They saw they lost the fight, and gave up.

Snaps predate (and do a whole lot more than) flatpak.

This does not contradict what I said: even if snaps are older Canonical is still pushing them as much as it can, because it can't control the alternative other distros would rather use (flatpaks). Or the distribution of software using that package system.

1 out of 3 isn’t great. (implied: "two of your examples are invalid")

Nah, 3 out of 3. False dichotomy and red herring aren't enough to discard either example.

But for the sake of argument let us pretend this was a 0 out of 3 instead. The point would still stand, given those are solely examples highlighting Canonical's modus operandi.

Speaking about the third example (Unity) you didn't mention: the situation was rather similar to Wayland: Canonical was displeased with GNOME 2.X, likely predicted 3.0 was going to be a trainwreck (it was), and then did its own thing instead of contributing with another project it wouldn't be able to control.

I think the general Linux userbase is so used to non-profit projects that it forgets Canonical is a corporation, and corporations always seek control.