As a 50 plus years GM Master…
As a 50 plus years GM Master Technician, I would have to say alignments are needed 2 times a year plus road conditions in your area. If the roads are crap like here in Colorado 4 times a year plus any time you hit a big pot hole. About every 10 feet!!! Weater it pulls one way or another or the stirring wheel is a little crock one way or the other; tire rotation, wheel balance, and alignment preserve tires. Do this regularly and see the maximum miles from your tires. But once a tire wear issue occurs the tire will continue to wear that way until you replace it/them! I was getting 30,000 out of old bias tires in the 1970's. Now days the tire shops keep telling my tires are old, out of date but still have 50% or more thread. Who says you don't need to do alignments? Someone who's full of Brown Matter!!!
MajorWeed