I partly agree but there are so many factors to consider.
The media we consume now, on all fronts, is completely oversaturated. To say that modern metal is sterile, as a sweeping sentence, is just untrue. I agree that the modern metal that is in the mainstream nowadays is, but there is just so much out there. You've gotta wade through a lot more mediocrity than maybe 30 or 40 years ago.
But, as Tommy said about the newer bands he likes, they are just recreating the sounds of the past. Tommy witnessed, and was at the forefront, of the birth of thrash, death and black metal. From there all the hundreds of sub genres formed. In 2022 there isn't really anything that can be done in metal that hasn't been done before.
The most innovative bands can really get is to just splice genres together, that haven't been mixed before. That stuff is out there, stuff that is groundbreaking to some extent. But it will be never as groundbreaking as literally forming thrash/death/black metal.
He mentioned the technicality of bands like Obscura. All these splintered genres were formed by bands just trying to create something new. There are a million death metal bands now, so one way to set yourself apart is to take one element to the extreme. This could be the lyrics, vocal style, technical proficiency, bpm etc. It feels that is all bands really have now.
Tommy has been in some legendary bands and influenced so many bands. Would he be able to say the same if he was born in 1993, instead of 1963? Probably not.
Also, let's be honest, the metal that was in the mainstream was better than today. It was actually more integrated into popular culture, especially in the UK. You'd get bands like Motorhead, Iron Maiden, Judas Priest, all on Top of the Pops! Back then, the majority of the population knew these bands, even I'd they weren't into metal.