It can be very harmful to act on an uninformed opinion. There’s also simply too much out there to be informed on everything, so logically there should be lots of things you aren’t able to have a valid opinion on.
People frequently get around this by finding people they think they can trust, and borrowing their “informed opinion” on things. But this can also be risky, and easily leads to groups with highly polarized opinions (political parties, etc). Even borrowing scientific/expert “opinions” on things can lead you astray, as we’ve seen with many of the funded studies on food health. Two experts can easily have conflicting opinions on something, with strong arguments/evidence to back up their stance.
So basically having completely uninformed opinions is dangerous, it’s not possible to learn everything well enough to have a good opinion on it, and borrowing others opinions on things only works some of the time. So it’s probably best to accept that you shouldn’t have a strong opinion on most things, and to be always willing to re-evaluate your opinions if you run into evidence that refutes your current opinions.
Honestly, it sounds like you’ve been spending too much time in some online communities that are doom posting about everything. Do things suck right now? Yes, but they’ve literally sucked for as long as human society has existed. Things can always be better, or always be worse. However you can’t just sit around passively waiting for the times to change, or your life will suck.
The single biggest factor in whether your life is good or not is you and your actions. Don’t let things outside of your control convince you to give up. Do the best with what you have, and I promise you that you can find fulfillment and happiness in the life available to you.