Aye, 1hbh is not dead, but is dying quickly. Just take a look at youngsters. Only prosperous one I can think of this moment is Dimitrov.
Wawring and Kohli also have good ranking and can produce some top quality tennis against top dogs, which they proved many times. But they are also relatively one of the old ones...
Not to mention Blake, who is probably the most affected by court speed changes.
I still believe 1hbh can parry this generation of 2hbh-ers.
So youngsters, if you are reading this: Don't believe all you hear, you can still have it and be as efficient as 2hbhanders