I also think it doesn't apply to me, but I worry about how really independent my thinking is.
2+2=4. But it also equals 8/2, 4.00000, and 25% of 16. What I've found in my experience is that when people disagree, they can both be right, and most often, the heart of the disagreement is not what is true, but what is _important_.
Another thing I've found to be true is that if you don't understand what someone is saying, they probably know something that you don't. These two findings don't seem related at first, but they are.
On politics different positions are rarely equivalent, but you're right that there's almost always truth on both sides and it's really expressing differing views of priorities and values. However, if you rank them by "which is best for human well-being" there is a best answer even if we can't know it. So one can't use this as a easy out "all opinions are equally valuable" kind of thing, which is just nonsense. Though one could argue that prioritizing "human well-being" is a value judgment, which it is.
I also agree with your last point, it's usually me who's misunderstanding something in that case upon digging deeper.
However, there are also classes of things that are objectively true like whether climate change is happening as a result of human activity. Or whether a politician said X or not when there's a video of them saying X. It's never 100% certainty in life, but some things are known sufficiently well that there's almost no chance of them being wrong.
Years of philosophical thinking begs to differ.
https://owlcation.com/humanities/Different-Types-of-Modern-U...
On those latter points, I'd go back to much of the disagreement being how much it matters. On balance, I agree with taking preventative actions because of the risk of global catastrophe. But I recognize that I don't know the future. There's a nonzero chance that global warming is less catastrophic than people expect, perhaps because we invent technological mitigations or because the Earth offsets the warming for cyclical reasons or in some kind of natural reaction to rising temperatures.
On balance, I believe we should work to reduce emissions and mitigate greenhouse gases, but I realize that it is just that, a belief, and I may be wrong.
However, there's no question it's going to be horrific to adapt to meanwhile. There's also a question of how much warming do we need to prevent an ice age, because ideally we'd want to stop there. Nobody asks these questions seriously though, and it could likely end ones career as a scientist to talk about it.
This assumes that “human well-being” has a single, objectively correct, ordinal measure, though maybe we don't know what that measure is.
That seems non-obvious, at best.