@Ashley *********
I don't know what powers you mean. Thailand lets you do the TDAC from 72 hours before arrival and up until the last minute. They even installed terminals airside in the airport, so that you can fill it out even after landing, and if you don't have a phone/wifi/whatever to do it by your own device.
On the other hand airlines are surely just making sure to cover their own behinds. If you were for some reason denied entry to Thailand after they flew you there, it's on them to fly you out again many times. They just want to be sure everything is in order before letting you board.
Personally I just entered Thailand again last week. And the airline (Thai Airways) at my check-in from Denmark only asked if I had done it. Didn't need to see it. Up to them, and nothing about the form itself. The form is just general information on who is arriving when.