And it might even be right and not get you in legal trouble! Not that you'd know (until audit day) unless you went back and did them as a verification though.
So going back to apples-and-apples comparison, i.e. assuming that "spend a lot of money to get it done for you" is not on the table, I'd trust current SOTA LLM to do a typical person's taxes better than they themselves would.
If a person is making a smaller income their tax situation is probably very simple, and can be handled by automated tools like TurboTax (as the sibling comment suggests).
I don't see a lot of value add from LLMs in this particular context. It's a situation where small mistakes can result in legal trouble or thousands of dollars of losses.