Your opinion is a little flawed in case of CEPEC. I never commented on cepec because Pakistanis were realy imotianal on this topic.
But now u have started seeing objectively than ask youself 2 questions:
1. What items china can send to other countries through CEPEC which cannot be sent at same price or at less price through Sea route?
2. After cepec how much more money china will make , than using sea route?
If , the answer is not a huge difference , than china will never do it with your terms & conditions
China has more benefits..commercial as well as strategic
First ,BRI/CPEC will get nearest port access for the western region of China ,which is vastly not industrialized
Second, with an alternate access to Arabian sea by passing Malacca straits China can ensure the continuous supply of critical imports like oil
After Tariff war with US many Chinese relocated operations to bordering Vietnam..inreality 90% of products are made in India..in vitenam they do the remaining 10% and past made in Vietnam sticker and export,there by bypassing tariffs and some times gets concessional duties in US as they are made in Vietnam.Similarly China can move manufacturing if the situation arises
another strategic benefit is ,China can make Gwadar as military base in pretext of providing security to BRI /CPEC or Chinese ships in region and can have higher hand in Gulf /arabian sea and Indian Ocean..also encircle India from west
The benefits are tilted most toward China.But if Pakistan can make use of the opportunities,they have lot of things to export to China and replace other countries that China depend on ,as there is a Free trade agreement making Pakistani imports much attractive to Chinese