This tends to be true of mamy of the artists that chart, but less so for indie bands. I see Major Parkinson's Blackbox and Magna Carta Cartel's The Dying Option as two of the best albums of the century so far, for example.
I don't think that's an accurate distinction. I think maybe it has more to do with the genre (e.g. more common in rock and less so in the electronic music that I listen to, where it's mostly EP driven).
If we're talking popularity vs indie, those bands seem pretty mainstream. In my head indie artists that put out single songs on Soundcloud etc don't do albums until they grow big, so pretty much the opposite (more popular = more album focused).