My impression is that epic bought them for sort of the same reason Microsoft bought linkedin. They don't make tons of money, but they enhance the pipeline of artists and musicians available to the game industry.
Of course I have no idea if that's why they did it, but epic has definitely shown interest in steering the direction of the game industry in the past, and aligning the talent pool with their way of thinking is maybe a good way to do that.
That would be SoundCloud. Bandcamp is a marketplace and a pretty good one.
The good news about this is that none of this should impact Bandcamp negatively, neither as a consumer or an artist, not unless you see more avenues to sell your music/merch as a bad thing. Bad news is your favorite Bandcamp artist will sell out ;)