I suspect the alignment is off, perhaps the equipment was not calibrated properly meaning the last alignment job was off. Or, you hit a pothole or something on the road and the rear alignment is off. Go to a different shop and have the alignment checked. If it is so far off as to ruin a tire it might be visibly off to the “trained” naked eye.
In a decent sized town you can often find a specialty “alignment shop”. This is a shop that handles difficult cases, and simply has more and better equipment and better trained techs. In this case I’d look for one of these. Or, spend a couple of extra bucks for an alignment at a Toyota dealer.