Nothing like Cleveland and/or Pittsburg by the late 90’s those families were already in serious decline.
In the 90’s the Dacalvs had ALOT of money making rackets.

1) They were on Wallstreet
2) John Riggi still had control of a couple of unions.
3) They still had their Brooklyn crew
4) Vinnie Ocean had whatever he had going on.

They did all the above after they were under the Gambino’s.
They were under the Gambino’s officially since the late 80’s.

You are pointing to being under the Gambino’s as proof that they are extinct.
Just a smaller family being eaten up by a bigger family.
Same thing happened with Philly and the Genovese family.
Genovese moved in by force and had Bruno whacked, but that wasn’t because the family was dying it was the opposite the family had big money making rackets that the Genovese wanted.

Similar circumstance.

Lastly it is again a known fact and generally accepted that the DeCalvs are under the Gambino’s
If you want to dispute that then you have to prove it not the other way around.