Argument of first world problems - WRONG!

[Dystopia]

Subject (A) - This problem exists because of reasons x and y and needs to be solved
Subject (B) - There are children starving in Africa, why care about that? / Compared to problems in third world countries, REAL problems, that's just an insignificant FIRST WORLD PROBLEM, it's not even an issue

I'm sure most of you have heard this argument, the abstract formula is, give or take, the following - I have knowledge of more important problems, therefore your problem is not important to solve / Since there are more important problems, your problem doesn't even exist and should be ignored / Taking into account other issues are not being solved, yours shouldn't be either / I lack knowledge and have never researched on that problem, therefore I consider it doesn't exist - And it's a first world problem / I'm going to wrongly equate your problems with others and given that others are bigger, yours shouldn't even be mentioned

--» This argument of first world problems represents a fallacy and shouldn't be used - I've seen and heard people using it all the time, in real life, on internet forums (including AF), and it's a treacherous form of addressing topics since people don't reply or provide evidence and simultaneously manage to somewhat get away with it

Here's why it's wrong:
1 - The fact more serious problems exist is not a reason to not address other problems
2 - The fact more serious problems exist does not prove that minor problems don't exist when compared to bigger ones
3 - Your lack of knowledge (Dunning-Kruger effect) and consequent behaviour or disregarding the issue as fake does not prove you're right if you provide no evidence
4 - Simply pointing out other non equated unrelated problems while failing to reply or counter-argument the specific topic at hand makes your whole reasoning a failure
5 - Attempts on purpose to use this argument to avoid answering don't work in your favour
6 - People have the right to fight and solve any issue they want, with the priority they want, and you have no right to tell people how to feel about it since it's a personal choice - Since it's worse in Africa and you're worried, go fix it yourself, just don't use it as an excuse to not fix our problems
7 - Just because from a personal standpoint you've been trough worse, it doesn't mean you get to tell me why I can't be sad, or frustrated or disappointed with something - Your suffering doesn't invalidate mine
8 - Equating the problem being discussed with another completely different and hardly unrelated, or even moderately related but still independent, and further arguing that because the later is not being fixed justifies not fixing the former is not a valid proposal
9 - And actually, fixing first world issues helps third world countries, because of our [western] influence over them, so it becomes a win win situation.

Anyone else subscribe to this? I'm tired of hearing this argument, it devalues the motion being dealt with and simultaneously allows the user to get away with it and sometimes winning the discussion [unjustly].