There is no such thing as 'permanent' renewal, and the Thai government is notoriously whimsical about such things. The trend is to make it more difficult for foreigners to move there, not easier.
There is always a risk in living and investing in a country where you don't have citizenship, because the government can always change the law in ways that make living there impossible.
A long time ago (but still in my lifetime), the government of Mexico decided they didn't want a lot of foreign businesses and foreign residents to own property in Mexico, so they expropriated all of it. One day you could be sitting in a beachfront villa, happy as a clam, and the next day the villa belonged to the government. No payment, nothing, just leave. Now it was dumb, and I don't think the Thai government will do anything like that, but the amount of money you need keeps changing. Some countries grandfather in such changes (Panama), but Thailand changes requirements and requires you to comply when it's time for a renewal.
Lots of people have lived there lots of years, so it doesn't mean you can't go. I think there are visas that require you tie up a fairly large sum of money in a Thai bank, but again, they are renewable.
If you do decide to do this, be sure to choose a place with an international school, preferably a choice of international schools. Anyone with money in Thailand sends their children to English-medium internatinal schools, it seems. The really good ones send most of their students on to prestigious overseas universities. They prepare students to attend Cambridge, Oxford, Harvard, Princeton, Stanford and other top universities.