Sitting at Ubon airport. This is the third time in 6 flights in the last 3 months with a 30-60 minute delay.

Maybe just coincidence or have others noted timing drifting off in this normally (and still otherwise) excellent carrier?

I am of the same opinion as the OP. About 50% of my recent flights have had significant delays.

Nok Air never had any punctuality to start with.

Only Nok Air and AirAsia fly domestic to my wife's hometown and we gave up on Nok and only fly AirAsia now as they are far superior in every way. At one point Nok was the only carrier to my wife's hometown and they were always late and still are.

One of the reasons I noted for Nok's lack of punctuality is their habit of waiting for latecomers.

AirAsia shut the door and go. I love AirAsia and invariably cheaper than Nok, believe it or not.

what town is that if I may ask ?

I can not see AirAsia being cheaper than NOK on virtually any domestic route, if you include all the hidden fees and surcharges.

In fact, to places like Chiang Mai they until recently have been usually the MOST EXPENSIVE carrier of all, including the full-service Airlines