A flight ticket isn't a "pretty standard" requirement. At an airport, maybe, but land border/river crossing it's not normal.
I remember hearing Ranong needed the extra stuff when they re-opened not so long ago, but it surprises me they persist with the extra requirements. Before covid I never had to show more than a passport there.
It's good people are bringing it up again to update that people should be prepared though.
You'd have to be committed to at least staying on for 5 years in Thailand to make learning Thai value for money & time expended as that money & time is very valuable for most people.
Do you even realize how many languages there are in the world? Thai doesn't even make it near the top 20 of most useful ones!