I take your point the majority are more middle aged / elderly working in these. However I personally know two sets of young guys running stalls and they love it. They’re from working class backgrounds and appreciate the freedom of running their own company. I think we’ll see a natural regeneration of hawkers, it only happens when the current want to give up or rents tip above their limits.
Oh I understand that these exist too. On instagram I was showed an ad about young hawkers having "innovations" to classic dishes, like Hokkien mee kosong, but of course they aren't the majority. I suppose the young hawkers competently use modern media to increase their reach.