Highway driving does wear out tires faster than just driving around town.
When you drive down the highway at higher speeds the tires are constantly making contact with the road at a high speed which leads to the tread wearing down faster than they would at slower speeds in town driving or city driving.
If you do a lot of highway driving then your tires tread will need replaced sooner than they would if you did just town driving or city driving.
With just mostly in town driving or city driving at slower speeds then you would likely still have plenty of tire tread left and still need to replace the tires as a result of age causing the tires to weather check and crack or the tread separating cause the steel wire in the tire then comes apart with the tires age.
If the tires are 8 years or older then it may be time to replace the tires regardless of miles driven on them.
Inspect your tires for bulges and cracks in the tread as well as sidewall.