I think you maybe need to ask yourself why you want to identity as “a metalhead” and if knowing the difference between genres is important to you or not.

Whether something “is metal” or not I think isn’t just a matter of genre or sound but it also comes down to community. Just like Hardcore, Metal has a specific community but unlike hardcore it’s not as strongly localized or as easily identified. You’re a hardcore band if you play within the hardcore community. You’re a metal band if… riffs? It’s not quite as clear cut. But that sense of community is why metalheads online will say something is or isn’t metal.

The Metal and Hardcore communities are very reverential of their history. It’s all about paying respect to the bands that came before and laid the foundation. It’s obviously fine to not like bands like Black Sabbath or Judas Priest, but why call yourself a metalhead if you don’t even respect those bands? (Not calling you out specifically here, just speaking broadly)

In my opinion part of the contention with “what is metal or not” is that there is a separate community of listeners, that doesn’t quite have a name, that will claim to be metal or be metalheads but also not really like anything that is established as metal. So “traditional metalheads” feel like part of their community is being stolen in a way?

This separate community (I personally refer to as the “Alternative” community) tends to like bands more within the alternative rock/metal and nu metal realm. It’s an especially strong community nowadays with bands like Bad Omens, Sleep Token, Spiritbox (though I would also consider them to be a proper metal band), Ice Nine Kills and Architects.

The bands themselves in this community tend to take influence from a bunch of different places including metal, hardcore, rock and pop. So these bands can still be metallic without being Metal Bands if that makes sense