I raced until I was 18. Even started a team in college.
If you never join a race or mogul team in your life, you will probably be fine and can certainly still become a very advanced amazing skier.
Racing does have its benefits though. You learn how to actually use your poles. Depending on the coach, training is pretty intensive and you end up working out every single day really hard. Some people do this on their own, but being forced to do it does help. You learn how to control yourself at high speeds in many different conditions. You learn proper stance and are a lot less likely to lean back.
It is usually pretty obvious when I'm out who has been trained and who hasn't when the person is obviously under 30. But as you get older, it becomes more difficult to tell because people either have so much experience to make up for it, or they have relaxed their style so you can no longer tell.
My first days in instructor certification i was getting asked constantly if I had raced. I considered it a compliment.
Racing doesn't really help you with powder/big mountain... at least my race background doesnt...... I feel like I'm learning a new sport. :)
And the comment above about mogul skiing...... You guys are crazy amazing skiers.... so impressive.