Best thing I ever did, besides marry a wonderful woman, was to 'claim' one room when we bought our current house. Gave her full reign over the rest of the house, inside and out, except for one room. It is mine, and I have complete control over what goes in and out. She doesn't 'have to' consult me over anything else it the house (but she does, because she wants me to enjoy living here, too) and I don't 'need' her approval to add/subtract what's in "my man cave", (but I do, for the same reason). She agrees it's total overkill, and I'm not done yet.
We all need a hobby. My father-in-law spent untold thousands stargazing and birdwatching (God rest his soul) . My father has spent untold hundreds of thousands for his ... 'hobbies' (and he's still going, at 85). Neither would change a thing , because they did / are doing what puts a smile on their face, and you can't put a $$ figure on that.
So, IMO, telling someone who is already here, to "get out while you still can" ... it's already too late. They're already here. There is no cure.
BUT... better to welcome new friends, with open arms. Maybe just for positive reinforcement... but it's too late for us, as well... the disease has no cure, so we just have to play nice with each other.
We can always disagree, but we don't have to be disagreeable. Like good neighbors.... Because we're all here, now. We're stuck with each other, and that isn't a bad thing, at all.