There is a pressure on sequels that can never be present during the first instalment of a franchise. The pressure to be equal or better than the first movie. The pressure to live up to the expectations based on the success of the first movie. Deadpool 2 had to follow up Deadpool, be better and funnier, and that is a lot of pressure. Even for a comic book character, who is able to break the 4th wall and survive pretty much everything. And sometimes that pressure becomes too much.
Only Deadpool could break a fourth wall inside of a fourth wall to achieve the ultimate level of awesomeness by breaking sixteen walls. And though it makes no sense, it doesn’t really matter, because I’m still sixteen levels of thrilled about Deadpool and the fact that its first installment won’t be the last.