I dislike Thrash Metal myself.
I see what you're saying, 70s-80s Metal seemed to use alot more treble-switch notes/riffs than modern day material, there's not much out today that sounds like 70s-80s metal but IMO there is far more diversity. Today's metal tends to use alot more distortion as well.
However I still humbly disagree with your previous statement, as I believe today's metal is far more diverse. Distinctive? Yes and No, because there is just that much metal out there now, it's near impossible to sound completely unique, and even those that manage to do so, people will say (they sound like this band, mixed with this band, mixed with this band, mixed with this band).
Today's Metal is heavier and lighter than 80's metal, I suggest checking out the Power and Neoclassical Progressive Metal genres, which I am not too much of a fan of (bar a few artists)
Not everything I listed was Black/Death, only some of it. I'll automatically assume you don't like Doom as well.
Everything in the long list is fairly "heavy" in one way or another, sparing the first two Atrox albums perhaps, however if you're a fan of classic metal you're probably not going to be interested in female vocal avantegarde metal either.
at least give
Opeth - Damnation a shot, if you don't like that, can't help you