Let’s play with an analogy.
Let’s think of rain as being a pest problem. If it rains, and your homes roof leaks, standard pest control methods would be like a bucket that you would use to collect the dripping water coming through your sagging ceiling.
Pest prevention would be like you, taking the initiative to repair your roof, so you could stop having to use the bucket.
You can re-use the bucket many times, but eventually, your problem will become much larger, and much more costly, requiring more buckets, and at some point, some serious and expensive repair work.
Unlike a bucket though, with normal pest control systems, you have to pay for them each time you use them, and you will have a growing and more expensive problem the longer you wait.
Wouldn’t it be smarter to repair the roof at the start? Of course it would! But, the roof only leaks when it rains…