This has been happening for years buddy.
There are tons and tons of these guys who just re-register and re-register over and over again.
Your idea is quite good (SMS validation) but chess.com will never do it because hey are interested in numbers, more than quality.
Many players of our level (plus friends of mine who are 2300+) have been talking to chess.com staff for years about this only to be fed the same robotic B.S about "If you suspect your opponent is cheating, please submit a ticket and we will look into the matter".
As a result, for me serious chess is played on icc or FIDE online arena (people are less likely to cheat on a paid account, and FIDE online arena links accounts to your FIDE ID which is even more deterring) and chess.com is more for coaching and some casual blitz.
Ive heard tons of smart proposals to deal with this cheating but chess.com does nothing. The cheating takes places at 2100+ level which is like 2% of the site population so its not important to them.
Anyway, whats the chess like in Thailand and Chiang mai in general?
Im in China at the moment but was considering spending a few months in TL.
Lately I've noticed a fairly large upsurge in the number of cheaters on chess.com that are using centaur based approaches. They cheat, but not the entire game. I can only imagine this was in large part inspired by a number of recent events not limited to Sniper No Sniping taking forever to get banned.
I will say chess.com is absolutely doing a much better job of getting rid of the cheaters than in the past but the problem is that I'll notice a player who was a clear centaur get banned and then within a day suddenly I'll end up facing a player who's playing strikingly similar and the process repeats.
Has chess.com considered doing some sort of enhanced validation for players once they pass a certain rating? Perhaps 2100? Something that's globally available including in very poor parts of the world would be a basic SMS validation. Your account is frozen until you enter a number and verify a basic SMS. Players could of course continue to play unrated games until verified.
You could even do similar enhanced validation for players if they want to, for example, post more than one time per day on the forum. Go check out the General Chess forum and it's nothing but spammers' posts on the first pages done by a tiny handful of accounts.
Are there any problems with this? It seems like an ideal solution to me. Perhaps you could even add an alternative snail mail validation possibility for people who simply and absolutely cannot use SMS (yet somehow can access the internet...). I'm sure the players who this would effect would actually be more than happy to do it since they're all going to be keenly aware and likey at one time or another effected by cheaters.
Of course nothing is going to stop an incredibly determined cheater, but I think getting a new sim card every time they get busted just to cheat on a chess server is a step that would deter the vast majority of cheaters.