Mosquitoes are the only natural predators of humans. If you mess with the delicate ecosystem, humans will procreate uninhibited and exhaust their resources, leading to a far worse fate. It's kinder to just leave the mosquitoes be, and let nature run its course.
Thailand is also pretty huge. You can have a vastly different holiday in Phuket, Bangkok or Chian Mai. A friend recently had a 1.5month trip to SEA and ended up spending the entirety just in Thailand since it's so massive
My back hurts