My understanding is that your fastest gains will especially be in your teens and your early-mid twenties. Then gains start to slow down and you have to be more careful with diet, training economy, recovery tactics, and conditioning.
But you still make gains through the 30's so the accumulation of all that work peaks in the mid 30's through the low 40's if you take care of yourself.
Now in a sport that requires great speed and reflexes like Olympic lifting, people tend to peak in their 20's. Speed, balance, and coordination peak in the 20's.
Whereas in powerlifting, there are many other qualities to being good at the powerlifts that continue to develop through the 30's and 40's.
I just recently turned 30 and I feel the fittest and am the strongest and most well balanced in a general athletic way than I ever have.
I plan on taking good care of myself so that I continue to be able to pick up heavy stuff even into the twilight years God willing.