I suspect politics are more discussed in forums where there is more “psychological safety” where the consequence of saying a thing that others disagree with doesn’t cause a rift in the relationship (as evidenced by the “it’s hard enough for a parent to make friends” statement).
The reason we can’t discuss politics is because we don’t practice. The widespread saying “don’t discuss politics or religion [in X context]” means that we have fewer places to discuss it, so we get less practice to do it. We are less practiced so it is brittle. If we practiced more, we would be more resilient.
Discussions about politics and religion are rife with conflation of opinion with fact, true fact with false fact, claim with evidence.
Most good faith differences on politics boil down to differing values and priorities. Having a discussion about those directly, rather than through the lens of the broken US political parties / election system is usually more productive in avoiding the screaming / emotions.
Then again, you could argue that the premise is flawed and we talk about politics too much…