As I've said elsewhere, up to the provinces, as some have imposed a 14 day self-quarantine period for arrivals from "dark red" provinces as so many clusters originated from Bangkok.
Locals can go and hide in the hills and on the farms, but tourists are rather more obvious so it's "welcome to Loei province. We hope you enjoyed your 14 day stay in Bangkok seeing the sights, but now you've got 14 days seeing the inside of your hotel bedroom. Nobody warned you? Oh dear ..."
Agreed 100% @Bob20, but that's up to Chiang Mai.
They're fully within their rights to impose a 14 day self-quarantine period for arrivals from Bangkok as other provinces have done ...
... so tourists can enjoy their 14 days seeing the sights in Bangkok or Phuket, but if they go to Loei or some other provinces they then get 14 days enjoying the inside of their hotel bedroom.
Oops ... didn't anyone tell them ?
Well Harry, most of these people haven't "really" been vaccinated either...
They received Sinovac
And a lot of them received it more than 6 months ago and their antibody levels have waned as well.
It's just like a new start...