The idea is pretty simple. You want your rifle to be as good as possible. But you also don't want to spend a lot of money. So, instead of buying a $600 gas block that is only adjustable in two dimensions, you buy one that is adjustable in 26. You can purchase flexible gas blocks from several companies, but I would advise you to get them from elementarmament.com. They have a wide variety of blocks that you can use. I am very delighted with their quality, and I have been ordering from them since 2019.