Would you agree that it somewhat makes sense (and is usually efficient) to correlate one's effort in solving some specific problem in some way to the severity of this problem relative to other problems (assuming all these problems are solvable)?

If this were the case, it would have been fitting for you to have written quite a few (maybe a few hundred) texts, discussing the problem "carbon/ecological footprint of exaggerated consumerism" if for the sake of simplicity we take length of text as a measure of effort invested in solving a problem.

Yes, it is possible to solve several problems in parallel. But putting a (hugely) disproportionate amount of effort into different problems when we're dealing with a set of problems of which some are arguably existential due to their order of magnitude, while others are absolutely not existential due to their order of magnitude .. well, doing that doesn't appear to make much sense (to me) and it makes me question whether the goal of solving the existential problems is really a shared goal.