This has been happening for the better part of a decade already. Back around 2012, I had already stopped seeing Vimeo come across my browsing history completely, but I was reminded of it's existence at a film festival where I heard about and saw vimeo being used to screen most of the more independent films. When I asked some of the festival organizers about how movies were screened, they said there were two ways (again, back in 2012): Digital Cinema Package (DCP) for more mainstream films (a DRM-laden harddrive package that was carried around to the screening location in a locked, nondescript hardcase), and password-protected Vimeo.

Since then, the only time I've interacted with Vimeo was to watch episodes of IKEA Heights[0], as at the time this was the only place where it was officially distributed (i.e. in original quality, rather than re-encoded and re-uploaded to youtube). Great, weird, short series if you are interested. The play between the drama/acting, and then being brought back to reality by being caught, is very fun.

If I recall correctly, this was around when they removed recommendation type features from their site, which was the first sign that I saw, personally, that they were moving away from something consumer focused.

The DCP system was intriguing to me. They made DCP sound like a pain in the ass, requiring expensive projection equipment and some kind of special internet connection (they weren't familiar with that part) to receive films not distributed physically or to receive updates to films. Later, I looked up DCP on Wikipedia[1] and found it enlightening. The thing that stood out to me was the use of asymmetric encryption to ensure a particular DCP distribution was only able to be played on a particular projector, thanks to a symmetric key for the film being encrypted with a projector's public key, and decrypted using the private key stored on some kind of FIPS compliant HSM.

[0] https://vimeo.com/channels/ikeaheights [1] https://en.wikipedia.org/wiki/Digital_Cinema_Package