Yes, for third country's nations signature campaigns can work greatly as a full time job, but only if you are fine with 1-2 wages monthly. it's possible to survive, but not to thrive and to live with confort, like everyone aims to live, I suppose. Chipmixer is an exception, though.
It's hard to say if someone lives exclusively from signature campaigns' income, because it's totally possible to work in something else and still post on the forum for extra earnings, without difficult or prejudice on your personal results. But I can say to live from trading is more unlike than living from signature campaign, due to the risks involved and long term outcomes.
Wages in third-world countries are generally low; we can't define their exact range, but still, I find it unlikely that they will solely depend on campaigns to survive. The minimum wage here is approximately $700; thus, a signature campaign is approximately 30–40% of our whole salary. Chipmixer is the exception to the rule; you'd live like a king here.
Some people think that it is their side job working in this forum, even though they have real jobs out there, but how can they divide their time to work on several campaigns that they participate in, at least not disturbing real work or signature work, if any someone who works all day long on the forum, of course they don't have jobs out there or are said to be unemployed, actually it's legal for them if they can share all that time, return to those who do it, in fact this will be a motivation for new users that not only in the real world to earn income, but in the Crypto world their income is valued more, rather than earning income in the real world.
Correct if my statement is wrong..!!
I don't quite understand what you want to say. This forum isn't meant to make you a living, and even if you're talking about campaigns such as Chipmixer, it's almost impossible to enter, especially if you're lacking the necessary knowledge. Most of its members are extremely knowledgeable and established users of this forum.