That last bit about the ads is key. Spotify, SoundCloud, etc. basically want to make sure that you only pay the right people to prop up your career vs. paying the wrong people. Instead of buttering up local promoters and flattering writers and tastemakers, DIY musicians get to navigate a world of zillions of digital gate keepers (real and illegitimate) with their hands out.
If you want to achieve something that looks like “success,” I’d say set up shop in a clearly defined genre and mine that genre and network aggressively in that genre’s fan groups and build it up from there with ads and giveaways as a steady stream of releases. With the digital scene, there’s a lot of benefit of not being too weird or too outside of established genre norms . Stick to a single image/sound/approach and focus on releasing stuff that is gonna sound right on a playlist next to other stuff in your genre. Make yourself easy to package and share.
Or prepare yourself for a lot of feedback like “I like it, but it doesn’t fit any of our playlists” or “this seems retro and modern...I don’t know what to make of it” or “what genre is this? I don’t know if our listeners will understand it” or whatever. If you get any “hey, this sounds like [iconic musician/band known for changing styles all the time and blending different sounds]” you’re probably gonna have an uphill battle.
If you are a guitarist type who wants to build an audience and rack up plays, start a hard rock/metal band that stays in one clearly defined lane. Or a shoegaze band. Or make music that can fit in on a study jams/indie coffeehouse/weekend chill out playlist with boy-girl vocals and bouncy folk pop vibes.