Why Is This A Bad Move?

So I was playing a match and I was in this position. The opponent just took my bishop, and I was planning on taking back. I am White BTW.

I played fxe3 but about 10 seconds later, I realized this was stupid because I could've taken with the queen AND defended that hanging pawn on c5, both of those moves would count as a "miss" because b4 is the best move since it kicks out the queen AND defends the pawn. What I find weird is: fxe3 makes the eval bar go to +0.59 but Qxe3 makes the eval bar go to +0.17. Does anyone know why this "error" turned out to be better than what I thought? Let me know in the comments.

The black queen and bishop both attack the pawn on c5, so even if you play Qxe3, the black queen will capture on c5 anyways.

Qxe3 allows Bxc5 with a tempo

i would play b4 with white in that position...

I'd think b4 is the best move

because fxe3 opens up the f-file for your rook, and bxc5 isnt possible because of b4.

what if qxc5

I agree cuz then the queen will move back and that same pawn defends the vulnerable pawn before u take the knight

b4 then eat the knight

B5

yea b4 much better