You fail to understand because of your agenda that has blinded you to the truth. Bluch problem aside, which exists on both sides of the border.
Even Americans are insisting on the fact that a new world order is being shaped in which USA will not be the same #1 superpower that it used to be and it will be challenged both economically and militarily.
Today Arab kinglets have realized the concept of that upcoming multipolar system and are already turning to China as a safe heaven for investors and as the biggest production line for every kind of commercial goods.
Gwadar will turn Pakistan into an economic hub for Chinese goods. USA, Europe, Russia and Iran and others will have to inevitably use that route provided by Pakistani port. Iran can import its required goods from Pakistani port, UAE is a shithole. Don't forget that UAE has earnt billions of dollars thanks to sanctions on Iran.
Imagine the amount of investment that will be poured into Pakistani ports and cities.
Iran has made sure that Arab kinglets cannot count on USA as the big brother anymore. So, there is a big chance Arabs shift to Chinese markets in spite of US pressure. Iran will make sure of it by keeping tabs on Arabs.
Moreover, USA's sneaky behaviour costed them dearly and its an Incredible chance to introduce the global markets with Gwadar and its potentials.
Iran will be the first investor, i guarantee it. Lol