Again, it's just not that simple.
I totally get what you mean, though. I go to small, local gigs all the time and always come out thinking how every band sounded the same as every other band. But on the other hand, you could have Slayer Band #24353 spice things up with new instruments and experimenting with different sub-genres, but then they'll still end up sounding like another band.
It sounds like you're just fed up with going to local shows where every band sounds the same. I get that, every metal gig I went to when I was in England was like that. Band after band of Drop C-Tuned guitars, with growling vocals that nobody understands, where the main weight of the music didn't come from the music itself, but how many blast beats the drummer can throw in, and how fast the guitarists can pick. Always left me feeling
