P2SH / Taproot disadvantage?

I had been living under the rock for some time, then I heard about Taproot, did some research, I think I get it (somewhat) technically:

• using Schnorr signatures for smaller multi-sig TXs
• using MAST in P2SH for small TX sizes even for large scripts with multiple UTXO spending conditions

But my questions are:

AFAIK, in P2SH, Alice (or anyone except Bob) does not know what the unlocking conditions are. After Alice locks Bitcoin using Bob's hash, no one knows how Bob (or Bobs) can unlock it.

I know someone can say it's "good for privacy". But with Bitcoin being a public ledger - Can it actually be a disadvantage? Is there a possibility of fraud by Bob(s)? Was P2SH a bad idea and does Taproot make it even worse?

Thank you for your ideas, and don't worry, I'm not going to defraud anyone.