access your video without going through steamit

Steemit is just a blockchain viewer for steem (the blockchain behind it) , we already have a few different ways to view it like steemviz,steemcrawl, understeem etc ..

platform would only have quality video

Quality according to who ?
I see the niche for a specialist viewer that display the videos however you wanted, and have them presorted by votes or amount of individuals referencing a specific video etc .. This is actually what I had in mind for steemvids.com

But this still doesn't require videos to go on the blockchain, and users could have videos appear there without ever leaving steemit or even knowing it existed.

This is why I asked specifically:

what the selling point is for uploading video to "steemtube" compared to uploading to youtube/vimeo/ipfs and embedding that video in a steemit post for free.

TLDR: IMHO we have "steemtube" now, all we need is a ui change and some imagination ;)