It's actually a pretty good example of a PWA which can be installed (depending on whether your platform supports it, works well with chrome and windows, sorta works on iOS but more fiddly. Havent tried firefox).

It can be, but I was mostly trying to list a benefit that the "good old" apps didn't have, i.e. not needing to install it.

That said, I'd also misunderstood the grandparent comment: they meant that it's a shame that Excalidraw is one of the few apps nowadays that have these features, even if the other ones also have advantages like not requiring an install.

Ah, but this business of being prompted to create an account also afflicts software that requires installation.

they do have a docker image (no collaboration though)