Because dtube is running on a decentralized blockchain, is open source and no body earns money from your content.

If you upload to YouTube - you give them the opportunity to earn money with your content. You don't control what is going on with your data. They can strike you, they can block you, you are basically a slave for them. that should be enough reason to not use YouTube in the first place.

Ah and your question: nope it would play back anymore. You need to pay the service before the video got deleted. Or you can also host your own ipfs-node and your own videos on it.
It is up to you - but dtube is not directly guilty for the deletion or f you videos.

YouTube is Google and Google is Powerful. Too powerful.
If they decide to delete your account - they will. You will never experience this with dtube.