Lars is a major influence on all metal drumming. I'd wager 99% of the drummers who put down Lars were directly or indirectly influenced by him.
The issue with Lars is historical context.
It's like a car that was state of the art in the 1930's, but that same car can't keep up with a even a mediocre standard production car of today.
In the 80's, Lars was doing things on drums few to no one was doing in a context where it was reaching people. His influence on young drummers was huge.
But as the 90's went on, millions of kids who grew up on Lars took everything Lars did, leaned how to do it, and then learned how to improve upon it, and took to new heights.
Lars himself went in opposite direction, got lazy, stopped practicing, and got to the point where he struggles to play his own parts.
There was a time that if you could play "One" on double bass, people looked up to you as having reached milestone in double bass drumming. Now double bass has so progressed that kids are born knowing how to play "One" and it's simple by todays standards.
Made worse that Lars so rarely practices (and readily admits it) that in concert, he can barely play "One" without sounding very sloppy.
Kids who weren't around in the 80's to understand the historical context see clips of Lars struggling to get through songs, then compare it to someone like George Kollias, Derek Roddy, or Thomas Haake, and Lars looks silly.
And even more so compared to someone like Dave Lombardo who has not only kept up his drumming over the years, but has actually taken the effort to improve his playing.