It depends on your settings? Are your toe-in and camber within spec? Maybe that's why most folk have an alignment done. If you feel that they are fine then I wouldn't worry about it.
Many times the alignment will be affected when work is done on the suspension. That's why people have an alignment performed. They don't know for sure but common sense makes them get an alignment so that they can be sure. The paperwork they receive shows before and after readings which shows if they actually did need an alignment. Otherwise they are guessing. You can gamble if you feel that you don't need one. It's up to you. What's the worst that can happen?
Many times the alignment will be affected when work is done on the suspension. That's why people have an alignment performed. They don't know for sure but common sense makes them get an alignment so that they can be sure. The paperwork they receive shows before and after readings which shows if they actually did need an alignment. Otherwise they are guessing. You can gamble if you feel that you don't need one. It's up to you. What's the worst that can happen?