Many foreigner lawyers/tax consultantants are grifters. Because Thai authoritiea don't watch what they say, they feel free to fear mongering and say false things to make money.
I agree. Also Thailand don't want this kind of people. Because as a foreigner you are a cost for them (police and other services) but no money to contribute. You are a liability. This is why they put financial requirements, to block broke people to live long term.
Don't blindly trust Reddit. The unlukiest people on earth share their experiences here, often they are extremely rare cases. Sometimes trolls post fake stories or they didn't write all the truth.
I would add that Onward ticket is very fast to buy, a normal ticket require more time so this MAY raise suspicions...probably the guy was already suspicious because i did go so many times in Thailand and IO never asked me a return ticket.
The ask:thailand community, consisting of multiple Q/A groups with over 100,000 members, powers this platform. It is not an official government resource. Our members actively contribute to this resource, and while we strive for accuracy, we cannot guarantee its complete reliability. Assistance to travelers is provided as a community service.