The only form of retirement poorer Thais have, is when they are no longer capable of working. Then they have to rely on what the rest of their family can provide.
600 baht/month at age 60, 700 at 70, 800 baht/month if they make it to 80.
Most of the families in my GF's village work on the rice farms, some go further afield as tradespeople or laborers. The average family income is around 3000 baht/month.
There's a very aged woman who walks between two villages to help clean up after funeral parties. She gets paid in food and the occasional 20 baht. She's quite delighted when I stop on the road and give her 100 baht.