Sadly, this site is filled with caregivers whose siblings couldn't/wouldn't help care for parents in need. For those who cared for their parents while dealing with absentee siblings, how is your relationship with your sibling(s) now?
This is on my mind because we just had the one year anniversary of my MIL's passing and no communication between my husband and his brother. Hubby had a good conversation with his sister that day but didn't care to reach out to his brother or hear from him.
Having said that I have noticed where the relationships of siblings only function through the hierarchy, parents at the top, everyone filtering through them when the parents die so do the relationships as they are not forged singerly.
Many parents control the family this way, my mother tried to do that with me and my brother, conquer and divide, but it didn't work. She wanted everything to filter through her, we were not supposed to spend any time together without her, sorry mother, not going to happen.
Now, due to her abuse I do not have contact with her, and never will again, yet my brother & I continue to move forward and fine tune our relationship.
But your husband's relationship with his brother is unique to the two of them, I don't think you can usefully compare experiences. These things never are set in stone and if it suits both then perhaps one day they will mend matters. Does it trouble you much, either way?