As one grows up,one becomes more experienced为什么用as不用when

在引导时间状语从句时
若要表示两个正在发展变化的情况,相当于汉语的“随着”,一般用 as：
Things are getting better and better as time goes on.随着时间的推移,情况越来越好.
As it grew darker,it became colder.天色越晚,天气越冷.
你的句子意思是：
随着慢慢长大,人就会变的越来越有经验
所以,只可以用as