Black doesn't have to move Rb8!
The move that kept me from leaving Chess.com?
if black plays 28. ... Rdd8, I play Rb7 and I see no way they can block the mate in two with Ra7+ Kxa7 Qb7#, other than by suffering serious material losses.
(engines say Black can minimize losses after 28. ... Rdd8 29. Rb7 with 29. ... Bb4... But I'd still be winning)
if black plays 28. ... Ka7, it's mate in three with 29. Rb7+ Ka8 30. Ra7+ Kxa7 Qb7#
if black plays 28. ... Rd7 to defend the 7th rank, I simply win material with 29. Bxc6+
if 28. ... Rgd8 then after I play 29. Rb7 they can defend with 29. ... R8d7. But 30. Rxd7 Rxd7 31. Bxc9+ still wins material.
If black takes with the knight at 23, it would be either 23. ... Nxb5 24. Qxb5+ Ka8 25. Qb7# or 23. ... Nxb5 24. Qxb5+ Ka7 25. Qb7# or 23. ... Nxb5 24. Qxb5+ Kc7 25. Rc1+ Kd6 26. Qc6#.
But I do agree that 28. ... Rb8 is one of the worst defenses Black can make. even a move somewhere else like fxg3 would be better.
Yes, I know people would laugh at the skill level presented in the game, but the title of the post minus the question mark is actually the truth... Comments I'd appreciate greatly because I need to improve my skills to prevent me from thinking about leaving Chess.com... again...