They aren’t forced to sign up, so they must see some upside in order to sign. Unless the implication is there is some corruption where people are selling their countries out for personal gain.
Well, the poor aren't calling the shots in most countries. Its the elite. Those in the ruling party and their friends. In terms of improving conditions for the poorest decile, its a bad deal. This is why we're seeing so much wealth concentrated with Musk, Bezos, Ma, Bernard Arnault, etc. And for those in the top 20-30% economically, a fair deal too.
The poor weren't forced to sign up. They're too economically illiterate to understand what's happening. And even if they did understand, they're not empowered to alter the outcome--even in democratic countries. It takes money to steer policy. Or a revolution.