The Thailand long term visa isn’t for digital nomads. It’s intended to attract wealthy individuals. Thailand grants few of those and they have mostly gone to Chinese and Singaporean nationals starting a business in Thailand. The income, employment, and degree requirements exclude the majority of nomads. I know the LTR visa gets called a digital nomad visa but it’s not.

DNs in Thailand usually stay on tourist visas or maybe retirement visas. Those visas do not allow working at all, even remotely, but enforcement is close to zero for obvious practical reasons.