If you have an income of $4000/month from your investments you should be above or at least very close to the $1,000,000 net worth requirement for the wealthy global citizen visa. Of course you'd have to take half of that and invest it into something that would significantly reduce the $4000/month in order to get the visa Thailand is a nice place but they are way overestimating the desire of people with money to invest or live there full time.