As an end user, a few things you should consider:
- Intuitive UI. It'S "too poolished" now, but it should also be easy to navigate.
- Availabiliy. I think an optimization in data transmission for faster loading times could greatly enhance user experience.
- No sign-up. Accounts are not of any help for end users and drive traffic away.
- Monetization. At some point, you will need to fund the server hardware and electricity & server maintenance. As we know, YouTube is basically ruined by ads at this point. Subscriptions are not the way to go either - long term they are going to kill you. My proposal: a system where you can watch everything for free, but for a tiny fee per video (for example, X [currency] per minute at resolution above X). make it free up to 720p or 1080p (depends on your budget, so probably 720p at 48 or 60 Frames per second). You could also go for colors - pay a small amount per video in order to view it in DCI-P3 instead of sRGB (so you can limit "regular" users into sRGB). Remember: whoever can afford a monitor which displays DCI-P3 reasonably well, can afford to pay a few cents to watch a video, too.
- Offline Availability. I think one feature many forgot is to download stuff. even a 720p video - if you download it, it seems to be interesting enough to download. They should be available as regular mp4 files, but playing it inside a proprietary ultra low data transmission player would also work (perhaps a program variant of the website?).
Good luck!