I often have trouble uploading larger file sized videos on DTube and there is no real way of knowing if there is an issue or not. My last upload was 6 days ago (because I've been busy) and the video before was a month in between uploads. I had to upload a few videos to YouTube and use "share2steem" to bring it over to Steem.

You might not have issues uploading videos, but many people do. I have always seen Steem Power as a retirement fund, so even if I only get a few cents for a blog entry or a few Steem for a video upload, I am powering up most of it. I heard the ratio is something like 13:1 Steem Power to Steem in your wallet for a good mix.

So I see DTube earnings as cumulative. It's also difficult to convert back to FIAT without jumping through some hoops.

I think the 7 day cut off does change the dynamic somewhat, but who knows what DTube might do in the future?