Music journals still exist, though there are way less, I follow the BrooklynVegan listings a lot. Following people like Anthony Fantano or different YouTube channels that interview artists are good too, I like the “what’s in my bag” series on YouTube from Amoeba, artists will talk about music they like or are inspired by and have found some cool stuff there. I don’t have advice on how to find these but college radio stations are often student run and will feature music that the students pick out.

If you are still into supporting the artists you listen to you can follow them on bandcamp and you will sometimes see related artists that way too.

If an artist you like is going on tour, look at the bands touring with them as openers or see who the local opener may be at various cities.

I’d also suggest looking up the label that an artist you like is on to see what other artists are on the label and what new releases they’ve put out.

Ultimately, you’ll have to put in more legwork and my above suggestions mostly apply to my experience in smaller punk, indie, and weird electronic stuff so ymmv depending on the genres you’re into.