I think what makes dealing with these people so hard is that you do end up feeling like you have to be quite brusque with them, in order to extricate yourself from their grip. Many of these types know good and well that you are trying to avoid being short, or brusque, or curt with them. They consciously use their target's reluctance to seem rude, in a manipulatve way. When you catch on to them doing that, you really owe them a bit of rudeness to correct their impression that you are some kind of a fool.

I've always tended to give people the benefit of the doubt that they are just caught up in enthusiasm for what they are wanting to communicate, and don't realise that they are hogging the conversation. That can be true occasionally, but I think I've assumed that more often than is deserved.

I have a lady friend who can be an excellent conversationalist, but just chooses to not "give" as much as she "takes." She loves to talk about her family and about how she grew up. I genuinely find it interesting to hear about people's backgrounds. I know she loves that attention from me. But, if I start talking about people in my family, she will actually stare into space, not make eye contact, and let all expression drain from her face. I think, the next time this happens, I'm going to say, "Forgive me for boring you. I really shouldn't talk so much. Let's get back to whatever is on your mind."

I am struggling daily about with my boyfriend's badly deteriorating health. He is in and out of the hospital. This same lady-friend of mine calls me and never thinks to ask how my S.O. is doing. When I've brought up his condition, she has said to me, "Because of how much illness there was in my own family, I really can no longer bear to hear about sickness and hospitals. It brings up too many painful memories." This gal amazes me with how imaginative and elaborate her strategies are for shutting me down, if I am taxing her patience. Now she is calling me and wondering why she doesn't hear more from me.

Here is an article that discusses the techniques that these kind of folks use. The article calls them "conversational narcissists." There really is a science to how they keep the focus on themselves:

Conversational Narcissism: How to Avoid It | The Art of Manliness