I have no choice. I can't get health insurance here due to a health condition so it's very effective for me. I generally fly non rev. So the cost of the flight is very low. The repatriation coverage in my accident policy is really only if I need a flight nurse and to equipment to fly home. Once home, my health insurance covers everything.
You can, but honestly it's much much easier if you have one. I go to the ATM maybe once a month to get a little money for tipping my building staff and
mine is 90 days. I usually travel every 2-3 months back home. Family obligations or doctors. Not a big deal. Never have to file 90 day reporting... Lol
Get annual travel insurance with repatriation. For the most part, high quality health care is cheap ( by American standards ). It's also possible to buy an accident policy in Thailand
Why get an OA? If you are in Thailand you get a Non O. No health insurance requirements. If the bank account is pricing difficult, get an agent. You pay once and then you can extend every year by yourself.
You can also apply for a Non OA while outside Thailand. You will have to get insurance but you will have an easier time getting a back account set up in Thailand.
The other two alternatives are the LTR ( if you qualify ) or the Thai privilege.
The privilege is the most expensive 650,000 baht fee, but it is the simplest to get. Takis 6-8 weeks to process due to criminal background checks.