In addition to the other comments pointing out the moat, it's also just a good product. There's some controversy here or there, but the watching experience is f

In addition to the other comments pointing out the moat, it's also just a good product. There's some controversy here or there, but the watching experience is fast and good, it's available almost everywhere (phones, laptop, smart tvs, consoles, ...), and it just works well. If someone hosts something on Vimeo, I always perceive that as giving users a worse experience just to make a point. Vimeo embeds don't sync how far I've watched across devices. It doesn't even remember it in a single tab on a single device. (Maybe that's because I don't have a Vimeo account but I do have a YouTube account. But that's part of the mount.)