I find it really useful to shut down discussions where no one is budging and are just overall a big waste of time. As an example, if I’ve been trying to convince someone that the earth is round for 10 minutes and they clearly don’t have any interest in changing their view, I’ll just spare me the trouble and say it. If they still refuse to let it go, I start blindly agreeing with them, that usually does the trick.
That’s why you play the puppeteer