The Gulf market and international market aren't awaiting for the Kaan, checking their watches every five seconds. The Kaan will have to compete with FCAS, GCAP, KF-21 EX, J-31, maybe J-20, and SU-57 or SU-75 for deals. It's possible that the majority of Kaans in service will be with the Turkish Air Force, rather than abroad. Kaan won't have the lower price advantage that many of our other defense exports have.
To add to Afif's points, the FCAS program is so dysfunctional that it is expected to be entirely in service in 2040. Here is
a link to Airbus's website stating as such about the project.
The J-20 is not for sale; if it were, the Chinese government would have already started to offer to sell it by now.
The SU-57 has faced significant challenges, with even India declining to purchase any. The Russians are struggling to put them into mass production, and the SU-75 is not expected to fare any better. Some reports even suggest that Russia has lost the ability to produce state-of-the-art fighters.
The J-31 has too much political baggage attached to it and not enough positives to weigh the negatives. One of the major negatives is that the purchase of the J-31 will not only piss off Americans, but it also doesn't come with the same level of political connections to make up for it since the Chinese have zero alliances with foreign policy.
The KF-21 uses too many foreign components in a way that is like the TB-2 of jet fighters, and it will run into the same problem as the Gripen. To mitigate this, the Korean government has started an indigenisation program, which will take a long time to achieve. The US will only let the Koreans sell their jets in place of the F-35 once the indigenisation process is complete.
The GCAP will enter service in 2035, when the Koreans developed their fighter engine. This is also five years after KAAN, with a domestic engine, is expected to enter service.