I visit Mom once a week, I live an hour away.
I had never had a good relationship with my mother. She has always been incredibly selfish and self centered and said many painful things to me when growing up. She and I are completely different people in so many ways, and wouldn't have much to have a conversation about. But that's ok, she just really wants to talk and doesn't want to hear what anyone else has to say anyways. Now with dementia, she is even more self centered and even more stubborn.
I don't do it because she deserves it. She doesn't. There's no well of good will to draw from. I do it because 1) I promised my dad 2) if I don't do what I do, then more work gets put on my sister and 3) I want to be the type of person who doesn't walk away from obligations just because its unpleasant. And it is unpleasant: she either cries of loneliness (but hates all my suggestions as to what she could do about that), is judgmental of other people (her sister looks old, this other one is fat), or complains about how rough her life is (family visiting every day, taking care of her bills, taking her out for drives/visits elsewhere, warm house, full refrigerator, all her needs being anticipated and dealt with) and that we don't do enough.
So I drive an hour plus, visit a couple of hours, do her grocery shopping and some food prep and occasional doctor visits. When my sister reminds me that she is doing more, I say that's your choice, and I am doing what I am comfortable with. Mom is being unreasonable on insisting to stay in her house, and is indifferent to the burden she puts on all of us to make that happen. I need to set my own boundaries, because no one else is going to.