In the prostitution game, the poor get poorer due to a lack of aptitude, not due to a lack of capital for their phones. Remaining poor due to a lack of aptitude is perfectly fair.
A long time off would bring in ~2000. About 3~4 long time offs should be enough to buy one of the basic smartphones, or perhaps a better quality used one. Anyone with zero capital should just cruise around the gay spots until he gets a client, then use internet cafs until he's had several clients & then he's good to go. Or work in a gogo bar until a suitable phone can be purchased.
Last month, I offed one Lao boy in Pattaya. I didn't check the details enough, but he's already a little plump, to the extent where it must be hurting his turnover & his performance in bed was such that my notes state "no repeat off".
Yet even he has a 1 month old 36,000 baht phone. So no shortage of working capital. I still suspect he will be struggling in a few years time, since he is blowing the money on luxury purchases now, whilst not putting enough effort into protecting his income stream.
There was another one who had a couple of offs with an acquaintance, then lost several thousand baht gambling & needed money. He told me what time he would arrive & asked me to wait outside my hotel. Instead of going to my hotel, he went to eat & called me after eating, expecting me to wait around for him to arrive 20 minutes late. Obviously I told him to go elsewhere. That one is also likely to always be short of money.
On the good side, I met a Cambodian farmer's son, who turned up on time, spoke good English, had a sensible phone, performed in bed and actually took the trouble to ask me if everything was OK afterwards. That one might get ahead.
The most careful ones put some money in the bank, buy sensible phones & take great care of their customers, so they might get repeat business.
So remaining poor because they don't try to be good with money is perfectly fair. People should take responsibility to be sensible with their own finances.
And if you think any other economic system is better than capitalism, well try going to communist Laos to see if living standards are any better there.