Channel banners It would be pretty cool if channel banners were added for better customization

Youtube this is like old youtube

Annotations allow users to quickly go to more videos, sub, or even find secret videos in a video.

Video Options the ability to change quality, speed, etc

Attract big youtubers to the site People like Markiplier, PewDiePie, MrBeast, etc. Get a time exclusivity deal with them if possible, but at least get them to upload to both YouTube and Vidlii. Make them announce it on their channels so people know they can watch them on Vidlii. This would all but ensure Vidlii blowing up in popularity and YouTube withering and dying. Once Markiplier, Pewds, etc. switch sites (pun intended), their audiences will follow. It's a guarantee.