The perfect is the enemy of the good.
We all see different injustices in the world. And we all have the right and responsibility to speak out against those injustices that we see, and that are important to us. I care a great deal about the social and political disenfranchisement of minor children in the western world.
There are other problems in the world. Wars, genocides, slavery, rape, starvation, epidemic diseases, as well as workplace sexual harassment, artistic censorship, and outdated traffic laws being enforced as a revenue instrument.
We are allowed to talk about what matters to us as individuals, even if what matters to us isn't "the worst problem in the world" by whatever standard you'd care to measure it. We're allowed to push for change on a "less important" issue even if we've never done anything to attend to a "more important" issue. And we should all feel absolutely zero shame in doing so.
Time spent figuring out what "the worst problem in the world" is, is time not spent fixing any problem. Fixing even the most trivial problem in the world is more important than wastefully arguing about who's problem is worse. Worse, by trying to draw people who are trying to fix a "minor problem" into that wasteful argument and force them to justify the time and resources they're spending on an issue, you're impeding someone who's trying to fix a problem, and making that problem harder to fix.
People can bring different levels of commitment and effort to different causes depending on how they feel about those causes and how those causes have impacted their lives. I can tirelessly advocate for youth rights even in the face of entrenched opposition, but my resolve gets drained quickly speaking out against a particular war.
That isn't to say we shouldn't try to convince one another that our causes matter, or that we shouldn't oppose those advocating causes we believe are harmful or evil. I just think it's high time we acknowledge that when we're trying to make the world a better place, following our passions and advocating for causes that matter to us personally gets more done than telling each other how unimportant the other person's cause is.