The way it was for me before streaming services and suggestions from algorithms, was that I would go read about artists I like via wikipedia or discogs. I have a pretty expansive and eclectic music library and almost everything came from following threads like that.

I remember seeing some version of Napalm Death at a festival and kind of liking it, that led me to the internet where I read about the original lineup and a guy called Mick Harris.. I saw he did a project called Painkiller which was mixing grindcore with jazz and dub and thought that may be cool so I bought a vinyl blindly on ebay… HOLY F*€K, John Zorn. that was then an ever expanding spiral as that guy is as prolific as they come and has worked with more people than I could count, and almost any style of music you could imagine. Following threads from the bass player I discovered Praxis, Mix Master Mike/turntablism in geberal, Buckethead, Jonas Hellborg, a load of great dub and funk, even going backwards in time to a love of Parliament via the Bootsy/Bernie connections with Laswell.

I have basically zero interest in Napalm Death and pretty low interest even in Zorn (despite his brilliance). None of the above demonstates my taste, but I found so much great music just by following those threads from every instance where I heard something I really enjoyed.

also it’s often worth checking other artists on the same record labels as most of the somewhat independent labels show some sort of interlinking qualities even where style varies (this is how I am currently exploring electronic music through my Aphex Twin obsession, with other Warp projects like Autechre and Squarepusher hitting me hard!).

Discogs is the best for finding actual working links between projects, and Wikipedia is great to find the out histories and influences of certain artists you like, which may lead to great discoveries :)

also if you really like a particular artist, find a sub of forum about them or something close and go ask there.. these places are all a mixed bag but usually there are passionate people with a lot of good suggestions :)