Your use case is simplistic so it dismisses actual use cases.
People make money on youtube through ads, you can't do that (as effectively) on your own server. This also ties with the analytics.
Some organisations like the ready-made administration solution. Uploading files through ftp isn't for everyone. Youtube (and hosting platforms) has a nice ui to manage all the content, handles the user authentication etc.
Bandwith.
Backups.
I aggree that for people who don't need all these, and are tech savvy, uploading an mp4 to a server is the way to go.
I think a bigger reason is all of those is the brand trust that YouTube has. If I, as an independent director, make a music video, or a 10-minute tutorial video, or a short cinematic film, and want it to be seen by tens of thousands of people this month, YouTube is where I'm posting it. If you can persuade me that there's a video URL that thousands and even millions of random strangers would be even more likely to click on than one that starts with YouTube.com, I'd be very grateful to know it. Even Vimeo is known to far fewer Gen Z viewers than it has been to Millennials -
People make money on youtube through ads, you can't do that (as effectively) on your own server. This also ties with the analytics.
Some organisations like the ready-made administration solution. Uploading files through ftp isn't for everyone. Youtube (and hosting platforms) has a nice ui to manage all the content, handles the user authentication etc.
Bandwith.
Backups.
I aggree that for people who don't need all these, and are tech savvy, uploading an mp4 to a server is the way to go.