Like every trend does on social media, it's devolved into another consumerist "spend money" issue, but on Tiktok and other places there's a trend of "going analog" and returning to old tech. Okay not "full analog" as some people were using mp3 players and 3DS as a way of returning to tech that doesn't talk you, and those are obv digital and not analog, but that's the overall spirit of the trend.
The issue is people are going out and buying shit instead of finding what they already have and repurposing it. Use an old phone without a sim card as an mp3 player, or get one used from a friend or a slightly more ethical marketplace rather than a brand new thing you might not use.
I just bought from Bandcamp last Friday cause it was a special day where all proceeds go straight to the artist. I made a neat little list of artists I wanted to look for on there, and most were on Bandcamp. Of the ones that weren't I think it was mostly because they're Japanese, so there's probably some other platform that they sell digital albums on rather than Bandcamp (Discogs was one of them).
You can download your music in multiple formats. The only thing that sucks is you have to download each album individually as far as I know. Some artists offer their entire discography in a bundle that's cheaper than individually buying each album, but do check if some of those songs aren't available for download anymore.
For me, I care most about having a working product and ethically consuming music as much as I can (afford lol), so the downloads and stuff is just quality of life things for me. I'm happy with my purchases and eagerly planning out a list of my next choices for September's Bandcamp Friday.
Also you can apparently stream on Bandcamp but i just selfhost a Navidrome and use that.