Oh wow that post went well
What I meant to say is: Prior warning - TL;DR
Seems to me what the "rock is dead" narrative complains about is that rock is no longer that genre which simultaneously enjoyed humongous chart success whilst also often being one of the more experimental and innovative forms of music. However this has pretty much been the case since the end of the 90s hasn't it? From the beginning of the 2000s commercially succssful rock/indie tended to be very backward-looking (though lots of it was still very good), whilst more innovative stuff would fail to chart (but might still build a substantial fan base).
So whilst it observes something that does seems to be really happening, the real question is whether the "rock is dead" brigade are simply overstating their case. I'd say that by almost any any criteria other than humongous record sales 'rock'/'guitar' music is still in fine health, if not the cultural behemoth that it was in the second half of the twentieth century
Are good/great rock records still being made? YES
Are there still rock records that could be said to be pushing boundaries/expanding the genre? This is a little more up for debate, arguably rock has tended to be more derivative than in previous decades, but I still think innovative and fresh rock records are being made.
Should record sales really be the metric by which a genre should be considered 'relevant' or 'influential'? of course not
Did any of what I just wrote make any sense? Probably not