Good response, I agree.
Leave the old guy alone and let him think what he wants. You're lucky to have him around.
Lucky? Do you know what that word means?
There is a ton of societal pressure for folks to keep good relationships with their biological family ignoring all other factors that can make those relationships completely toxic to them.
If my parents only talked about conspiracy theories (and my dad does talk about them, just not constantly thankfully - it's often enough I empathize with the OP though. we're lucky in that we now have kids to "distract" from the conspiracy crap that otherwise dominates conversations) I'd probably slowly reduce contact. I was doing that prior to #1 being born because the stuff around 2016 was crazy then too.
My parents (father especially) do not add much value to my life on the whole in spite of my having spent many years trying to improve the relationship. I would lose little by just not interacting with them much at all, when I look at it objectively.
Maybe you are blessed with a great relationship with your parents. Not everyone is.
OP's father clearly disrespects the OP if they ignore their wishes in 75%+ conversations and disrespect them enough he "angrily hangs up."
The idea that OP "owes" something to their father to fix them or whatever and bear the emotional burden their father puts on them without having any boundaries is just... not ok.
Now it's possible the OP has a deeper connection to their father than I do mine, and feels more responsibility than I do for "fixing" him, but I just don't engage on my dad on this stuff. He's going to believe it regardless of what I say. I am 100% convinced of this. I spent many years trying to have a better relationship.
OP I sympathize with you. My recommendation is figure out what boundaries you want to set, set them, live them out, and periodically reevaluate them.
You may also enjoy the book I'm reading here
https://forum.mrmoneymustache.com/welcome-to-the-forum/who-is-reading-'adult-children-of-emotionally-immature-parents'-with-me/If your situation is similar to mine, you're going to read that book and go "wow! this... is written about my dad."
Yes, he gets to make his own decisions. But that doesn't mean OP shouldn't try to figure out where these ideas are coming from. He's spouting internet conspiracy theory talking points, not original thoughts, and it seems to be consuming his life in a completely unhealthy way. If I ever go that way . . . oh dear, please someone stage an intervention!
My kids already told me they thought my twitter was toxic. Not "Mom your ideas are wrong" but "Mom, your twitter seems toxic. Mine's all about sports." So I ditched twitter. It was as simple as that.
I've already told my kids that I plan to check myself into a senior apartment hopefully well before I need it . . . and to please talk to me about giving up my car keys if I seem to be having trouble. I have promised them that I will not be difficult about it, and to please remind me that I promised not to be difficult. While I trust my kids, is it possible that one of them might have a spouse who tries to bilk me out of my millions, but I'm not going to worry about that until there are signs of it. Probably they will just marry nice people and do their best to take care of loopy little old Zamboni.
I cite Granny as an example because I do not want to become her. I also hope my kids WiLL protect me and my stash from predatory contractors, phone scams, religious and political cults, etc. when I start losing my critical reasoning skills.
I would not assume because
you feel this way about your kids and empowering them that every parent has a similar dynamic so.
What you are saying is completely the opposite of how my dad (and presumably OPs dad too) have interacted with their children.
I'm glad you are a great parent and trust your kids. I have never once recalled my father asking for my advice on anything and I am in my 30s. The idea of him deciding to take unsolicited advice is... well. I empathize with the OP's predicament.