When I was a dental student we were taught to remove wisdom teeth if it was likely that they would cause problems in the future. Now, much more sensibly, we leave them in place unless they are causing repeated or constant problems. One thing wisdom teeth DON'T do is cause tooth decay.
Crowded, overlapping teeth can make it difficult to clean properly, increasing the likelihood of gum trouble and tooth decay but, contrary to common belief, wisdom teeth are usually NOT responsible for crowding elsewhere in the mouth.
I hope this helps.