Kirk here. This has gotten a fair amount of coverage in Japan. At first, I had trouble verifying it in English but I was finally able to do so. The overall rating for the airport is 4 stars (out of 5) and there are airports in the world with that 5 of 5 rating. But, for a little regional airport. I think Aso Kumamoto Airport is doing quite well.
https://skytraxratings.com/2026-world-airport-awards-are-announced