It's common for bands to go raw/heavy -> light/poppy. Any examples of opposite where a band got progressively heavier?

Metallica, Opeth, Between the Buried and Me, Mastodon, Gojira, In Flames, Underoath, Ulver, Behemoth, Dimmu Borgir(added more symphonic elements and operatic vocals, less nasty black metal parts), many more to name.

I feel like they either lose their heaviness and become more "radio-friendly" - lose the growls, blast beats, move from being heavy riff-driven to vocal driven. Or they bite the prog bullet and shift to a straight up prog rock or experimental. Either way, the trend seems to be mellowing out.

Are there any bands that have done the opposite? Ditched clean vocals, incorporated brutal riffs and blast beats or shreds, got progressively heavier and less mainstream?

I realized I literally can't think of any. Is it just that musicians age and can't keep up with the headbanging, speed, or brutality?