Just calling someone dumb isn’t constructive. Instead tell them what you think Bandcamp had to offer.
Plus multiple download formats, including losslessly compressed formats such as FLAC.
Plus the best return to the musician of any similar platform.
Actually, you can! Fun fact, unless an artist/label has explicitly limited what you can listen to without having made a purchase, you can listen to most of the music on Bandcamp in full, without buying it, an unlimited number of times if you're not logged in. The way it works is that, if you're logged in, you get a set (~3?) number of listens before Bandcamp basically says, "Yo, you seem to dig this, you should prolly be a mensch and throw some dough to the artist(s)/label." If you're logged out, I'm not sure what the limit is (if there even is one?), but it's likely easily circumvented by clearing cache/cookies.
There are decisions that can be made by some artists, although I don't recall being offered "full preview requires signin" when I put my own album on BC.
This is what made me love Bandcamp. I get to pay the artists more-or-less directly, and as a person who tends not to be into the Big Music Names, Bandcamp is utterly amazing, chock full of smaller artists doing wonderful things.
How so? There aren't necessarily any upfront costs for getting on Spotify; several aggregators offer a "we take a cut of your earnings" model.