Poisoned Rook?

As far as I can see, Black is clearly winning, and yeah, why can't Black take the rook

i don't know either, but im bad at chess and only see the pawn on c4?

The rook is okay to capture. I'd probably take the d5 rook.

The move ...Bxd5 is only a few centipawns "worse" than the "better" moves ...Rae8 or ...a5. These moves are okay positionally, but with a deeper engine depth, they may even realize that ...Bxd5 is best. This is why it's important to understand the ideas instead of just blindly accepting what the engine considers "best."

The reason that the engine chooses other moves instead of the "free material" (of ...Bxd5) is because black was already up material in the starting position and at the higher levels, it is important to have more material, but less important of how much more. Imagine if one side had an entire extra queen. In almost all positions, that side would be winning because 9 points of material is a lot. Now what if one side had two extra queens? That's 18 points of material, but is that twice as good as 9 points? Uh, not really. Up an entire queen is going to win probably like 99% of the time and up two queens will win like 99% of the time, so the overkill lead in material doesn't really help all that much. The higher rated the players, then the more accurately they can convert with less material. Most players can win with an extra queen. Advanced players can win with an extra piece or maybe even just one extra pawn.

Computers are way better than human opponents, so being up material, they don't gain much more by grabbing more material, so they can just ignore it. A win is a win, so the computer is already winning and may prioritize a developing move like ...Rae8 over taking "extra" material.

If you aren't as confident with converting just a single pawn into a win, then you can check out this video I made on how to do this:

It's not the engine says we shouldn't take it, the grandmaster who played the game said that, and when his opponent gave up the rook, he said "威胁比实施更可怕，这个车咱们他就是不吃，我看你怎么办" (Threat is more terrifying than implementation, we just don't take that rook, what could you do?). Maybe he's wrong. No one can give me a clear answer, even stockfish, so I sent it on a forum to see if anyone can answer me.