I mean it was the default environment on Ubuntu distros for years...I would say it was more forced than Snaps are.

I don't know if I'd agree; with Unity you could just install a new DE & switch environments without fuss.

My biggest problem with Snap is that trying to install something like Chromium via apt, will, most likely unbeknownst to the user, just install the Snap version instead.

This.

I recently installed Chromium via apt, and it actually installed the snap!

I mean, if I wanted the snap I'll use the snap command. If it's not available via apt just say so and quit. I don't want it to install the snap version when I asked for the apt (.deb) thing.

In this particular case the means to the end matters.

Well ok, maybe "forced" was the wrong word choice, but I would still say Unity was a more in-your-face change than Snaps are, since the vast majority of software on Ubuntu is still distribute via proper .deb packages