Why did black resign in this game? Watching this video, it seemed after the highlighted point in the video that black was doomed, but from my view it was just materiel?  After the exchange, white would have taken a rook and the queen (and trading white's own queen) leaving black only a bishop vs. two white rooks.  Is that why black resigned?  Obviously at that point black would have been at a big disadvantage.  But I'm curious if there was a compelling mate opportunity for white above and beyond the materiel advantage.  Here's the video:

https://youtu.be/APJ5E1wXB3g?t=1631

(Also, I'm confused why the YouTube video refers to this as a "Queen sacrifice" since the queen wasn't in fact sacrificed?)
Because he is losing the Rh8, and at that level, that is an EASY win. It is also worse than that as mate is coming in a few moves. Even without the almost immediate mate, being down a pawn and an exchange is a lot of material.

By the way, although black did not take it, white did offer a queen sac on move 24.Qg7, but had it been taken, a new queen would have appeared next move.

 [FEN "2q4r/2rbkp2/4pQpP/pp4P1/4P3/5P2/PPPR4/2K4R b - - 0 1"]

 1... Kf8 2. Qxh8+ Ke7 3. Qf6+ Kf8 4. h7 {And mate after a couple of spite checks on c2.}


Here is the full game:

 [Event "EU-ch rapid"]
 [Site "Tallinn"]
 [Date "2019.12.05"]
 [Round "1"]
 [White "Aizenberg, Benny"]
 [Black "Guseinov, Gadir"]
 [Result "1-0"]
 [ECO "B77"]
 [WhiteElo "1995"]
 [BlackElo "2691"]
 [PlyCount "55"]
 [EventDate "2019.12.05"]
 [EventType "swiss"]
 [EventRounds "13"]
 [EventCountry "EST"]
 [FEN ""]

 1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Be3 Nf6 6. Nc3 Bg7 7. Bc4 O-O 8. Bb3 d6 9. f3 Bd7 10. Qd2 Nxd4 11. Bxd4 b5 12. h4 a5 13. Nd5 Nxd5 14. Bxg7 Kxg7 15. Bxd5 Rc8 16. h5 Rh8 17. O-O-O Qb6 18. g4 e6 19. h6+ Kf8 20. Bb7 Qxb7 21. Qxd6+ Ke8 22. Qd4 Rg8 23. Rd2 Rc7 24. Qg7 Rf8 25. Qxh7 Ke7 26. Qg7 Qc8 27. g5 Rh8 28. Qf6+ 1-0