If Vimeo has no value-add, then that's what people should be doing. It's not like Vimeo is a platform for content discovery like YouTube so it should be no problem for anyone to switch.
Also services like cloudflare stream/bunnycdn stream/mux are fairly recent.
Another issue is reuploading of all the media. It's not that easy to switch. But people will flee to some other solutions.
However, it's essentially the same service otherwise. Point your customers or business partners to a URL and they stream it from there.