I'm sorry to be so negative, but this is a widespread issue affecting 3080 & 3090 alike and I highly doubt that reviewer just got a TUF which works properly. Probably he just didn't notice because the issue can take a while to appear. You can be just browsing and the fans will remain at 0%, so...
3090 TUF OC user here. Exact same issue: fans spin on idle at 53%. Always the same percentage, then go back to 0%. Not a temperature issue because it stays at 29/30º.
I don't understand how could this obvious issue bypass QC.