[IANAD]

> there will never be another Rock genre in terms of popularity

That is purely based on your recent experience, and I believe it to be short-sighted.

As an example, Classical Period music was popular roughly between 1730 and 1820. That's 90 years- in comparison, Rock is only about 61 years old.

Rock will no doubt continue to influence future musicians even when it is no longer the predominant form of popular music. But, assuming history repeats itself, which it tends to do, Rock probably won't be the last popular form of music spanning several decades.

And I believe what will replace Rock will be some form of electronic pop.