It looks very nice, congratulations.
But I must make some technical suggestions,
Don't use whole MP4 files, it's painful for the hard drive to have to open a large file to scroll to a certain part and then send the requested bytes, and then do this operation hundreds of times for each visit is not optimal, it's better to use chunks of files.
Avoid being Hotlinked to mp4 files
Research the HLS format, and use it, you can easily integrate it into your player, and you can allow videos to be stored with chunks.
Use a CDN like cloudflare, to avoid DDOS attacks and to hide your real IP, obviously you should also use it to cache the content
Save the chunks with another extension like .gif or jpg (even though they are really mp4) this discourages your content from being stolen and forces the CDN to save the chunks in its cache.
Autoplay the videos
7 Cloudflare can help you give responses with HTTP/2 and HTTP/3
Currently the responses are HTTP/1.1
All of this is optional, but they are tips that I applied at some point on my streaming site, although I didn't grow much, I managed to serve 3 million monthly requests and many people watching live videos with a $5 server.
Otherwise I wish you much success