you made a new recipe of chocolates that made you go millions in a month, obviously if someone were to stole that recipe your business will fall.
patents is there to handle thieves, either by making a contract where you make them pay a monthly fee or a percentage of their income, or banning them of the rights to have your recipe.
That is a simplistic way of looking at it for luxuries. The clothing industry has really poor protection, yet there are extremely expensive brands.
They can also be exploited, say you and a competitor think of that new recipe, you file for it first, get it and do nothing with it for the entire duration. It wouldn't fit in your market, yet it also stops your competition, so you still have an indirect profit from it.
There is also the case of too broad patents being awarded for a too long time, blocking entire industries to one company.