While "politics is hard mode" is technically closer to the truth than "politics is the mind killer", it fails to serve the phrase's social function as well.

There is a common adage that good startup ideas are worthless. This is false. However, there are a lot of people with bad or not-unusually-good startup ideas, which they think are great, but which aren't worth spending time on. It is usually bad to tell people that their ideas suck, or that they aren't even worth listening to. So instead, we have a standard piece of wisdom that all startup ideas are worthless, and use this to deflect frustrating conversations in a way that won't cause offense.

When a political topic comes up, I look around the room. I predict who is likely to be triggered, I check my own mental state, and I predict how the conversation is likely to go. If I expect it to go badly, I say: politics is the mind killer. It's not you, it's everyone, now let's talk about something else.

(Sometimes I forget to do all that, and regret it. And sometimes "the room" is a public thread on the internet, which usually means fools will come crawling out of the woodwork.)

(Please don't explain this to people who would be hurt by that knowledge.)