Never felt the need to 'rotate' tires. I generally get 2500-3000 miles service for rear tire, and twice that for the front. Replace rear twice as often as the front. So I buy my tires in multiples of three.

That rough guide has worked for me for the past 40 years. Tires may have improved in treadlife wear, but now I'm putting 50% more weight on them than I did back then so the end result is about the same.

(sigh!)