Sounds like your only criteria to calling them overrated is you dont like the Niners.
If you want to claim they are not the best team in the league you could probably get actual data and prove that. I dont think any Niners fan thinks they are perfect.....but it's been fun to win games which is something they have done.
Does the offense need work....you bet, it's not perfect at all.
I just dont understand your claim of them being overrated.