When My dad died I sold his office and bought a house. The office would have been divided but I asked my brothers and sister to give it to me and they were glad to do that. I took care of both my parents when they got older. Everyone else was busy making money and did not have time to do anything for them.
Yes, it seems that on many occasions God selects the one sibling able and willing to care for the parents. In my family it was like this but a bit different.
My brothers and I were all equally responsible and willing, but took on different roles. My wife and I visited my surviving Mother for maybe 10 years on an almost weekly basis, while my brothers were busy with their own families, lives, and finances. They almost never visited my Mother.
But when she died the other brothers took up the legal cause, and completely eliminated us from the equation. I was better with money than they were, but they were very honest and dilligent under the law. We lost a lot of money on a care facility, because they wouldn't let us rent her house and wouldn't let us care for her in our own home. But they did manage things to a respectable end.
In many families, some feel marginalized, as we felt. But it works out respectably if you have a respectable family, with all members doing their job. Unfortunately, that is not always the case.
My wife's Mother was taken care of for a few years by her nieces, though the finances were already taken care of. When she died, the nieces took a larger chunk of the inheritance than was warranted, the Mother having changed her will on their behalf. It's not always fair, but people get taken care of, and life moves on.
In your situation I think things turned out well for you, if you were able to get a house from the office sale? You certainly deserved it, having taken care of your Dad. And I respect your siblings for letting you take the office.