Steemit is just (one of the) acesspoint to the steem blockchain. Videos dont go into the blockchain as you might imagine, in this case its uploaded via dtube. That wont get much better by itself, let alone similar to youtube which runs on a huge decifit and has constantly money pumped into it from google.
On the flip side, anyone can just put his own ipfs node up and pin his videos to reliably deliver them to anyone who wants to view them.