This is the 13892nd most frequent Korean word.
많아지면
"To increase" or "to become more."
Here, '많아지면' ('if it increases in number') is used to indicate a conditional situation where the quantity of 'people' grows.
사람들이 많아지면 자리가 부족해질 수 있어요.
If the people increase in number, there might be a shortage of seats.
In this sentence, '많아지면' refers to the rise in quantity or frequency of 'problems,' again using a conditional framework.
문제가 많아지면 해결하기가 어려워질 것입니다.
If problems multiply, solving them will become harder.
Here, '많아지면' is applied to express the increasing degree or abundance of 'complexity,' leading to an impacting outcome.