There's no need to aerate your lawn unless you're aiming to have a very healthy and very nice looking lawn.
Aerating your lawn helps the grass fertilize and grow in a much healthier way and gives your lawn a nicer look however if you don't want to aerate your lawn you don't need too.
My grass stays pretty nice looking green in the spring and summer even though I never aerate the lawn so it's not really necessary to aerate the lawn.