These people need professional help, not enablers. They range from immature to sociopathic and need to be treated as such.
Life is much too short to develop the Cognitive Dissonance required to interact with them. There is nothing you can do to make them happy and appeasement only makes them demand more.
Since doing it, it's amazing how much more time and effort I can share with others who aren't messed up. You don't realize how much effort you're wasting with them under the 90/10 rule until you stop. I enjoy time and interactions with the 90 since dropping the 10 completely.
Some use the analogy of "anchors and sails". People can be either one - their choice. Why waste time with "anchors" when you can go forward and grow with "sails"?
Others may argue "turn the other cheek" and that outreach can get them to change. Others may have the patience and fortitude for that, and kudos to them. I had to accept that my own upbringing caused me to get sucked in and be, at best, an enabler. For their sake and mine, I can't be their enabler.
As the old Italians say, “When the donkey brays, don’t answer it.”