In the event of an unexpected attack, “outdated” F-16s and F-5s stand no chance against more sophisticated opponents, and one Gripen fleet is definitely not enough to serve as a credible air deterrence.
All key U.S. partners in Asia, except the Philippines, now have (or are about to have) F-35s, enabling them to enjoy greater interoperability with each other. To maximize its security, the Thai military cannot afford to be left out of this new defense “inner circle.”
https://thediplomat.com/2022/08/thailands-awkward-pursuit-of-american-f-35as/