Is Classical Chess Dying? Should Blitz, Bullet and Rapid Take Over?
Yes. Classical time limits were introduced when chess was a sort of scientific endeavour and people were discovering new things about chess all the time. Modern chess is no longer about breaking new ground but rather by incorporating what was gained in the past. Any last remnants of the idea of progressing chess theory have been blown out of the water by computers.
I assume the old time limits were originally devised to try to allow someone with good strategic play and sound play to win over just tactics/calculators. Now all the top players know all the ideas, so it comes down to more calculation This is not to say there is no strategy in modern chess, of course there is, but it's generally all been seen before in one form or another. So since it is generally all about calculating and remembering now, I see no reason why not them under pressure at it.
Also a large proportion of GM games only last around 5-10 moves these days - moves of new theory that is. So while in the past they would have 20+ moves after coming out of theory now it's a fraction of that time. It therefore makes sense they would need less time.

This topic will spark debate between traditionalists who value deep calculation and those who enjoy faster, more exciting gameplay style.
faster will always be a secondary thing, no matter what we who enjoy fast chess think.
I enjoy fast chess but slower controls are far more satisfying for good players. The fact that they may not be satisfying to weak players or to strong ones who are bored with chess doesn't alter the reality.
I mean, you can have faster, more fun rubbish chess and if you're a weak player, that will seem best.
This topic will spark debate between traditionalists who value deep calculation and those who enjoy faster, more exciting gameplay style.