I haven't proposed anything, I just stated why the fairer distribution of listening time from subscriptions doesn't exist: the major labels will lose money they get from having a split pot from all subscriptions.
Your example makes it perfectly clear, even though BobTunes has 730 hours/month in this example from Bob, in the aggregate of all users listening time their share % of total listening time will be much lower than the total listening time of Ed Sheeran; Ed Sheeran will have millions of people maybe listening a few minutes/an hour while BobTunes might have low thousands, you'd need every BobTunes listener to stream orders of magnitude more time to compensate.
In the current scheme, having major artists with a broad audience listening a little gets a share of the pot that every subscriber funds, for the labels this is great, they make money from the total pot even from non-listeners of their artists, smaller artists from indie labels get a smaller share of the total pot even if they have mega-fans that only listen to them.
That's exactly why the system you describe doesn't exist, the major labels would lose money since they won't collect a share of the pot from subscribers who aren't interested in their artists (like me, for example).