frankly I think it's silly to call it Satanism since none of the modern Satanic churches even really believe in a devil. They're really just doing it to get a rise out of Christians, which, while a noble purpose (fighting for the US government to stop giving christianity special treatment under the law, specifically is what I am referring to), isn't really accurately depicting what they say, do, or believe.

the only satanic churches I know of are:
- Anton LaVey's Satanism (Church of Satan), which doesn't actually believe in Satanism and is more like if Ayn Rand made a religion and latched onto satanic imagery, and is mostly defunct since his death (at least that is my understanding)
- The Satanic Temple, an atheistic/agnostic organization focused on giving equal time to alternate religions when US governments show things like ten commandments monuments in courthouses. Personally, I understand the desire to troll these kinds of christians a bit, but I don't think it's actually helpful to give them something to rally against; they're already so out of touch with reality, and giving them an actual thing that fills their imagined devil that they can rally against only makes them stronger. So, while I respect the work they are doing, I don't think they're doing a very good job of it, but I do get a chuckle out of some of their shenanigans, like After School Satan.
- The Temple of Set, a bunch of ceremonial magicians who worship the Egyptian god Set, and have been looped in with satanists & satanism before, even though they are ostensibly called setians and practice setianism, which I guess sounds similar? idk.

I'm sure there are others (and can see that there are on the wikipedia page for satanism), but I've never heard of any outside of these three.
Personally, I think Christians misunderstand what Satan is meant to be in their own religion and that modern Satanism seems to not actually be any kind of Satanic worship whatsoever, so I don't fully understand why they chose to call themselves Satanists, other than to just seem edgy?

tl;dr: I don't super get it, but I don't really have any strong thoughts/beliefs about it.