It is an interesting thread. I think when you're younger and both parents are around, you are made to feel as if you have to be best friends for life with your siblings, which isn't realistic for everyone. It's lovely to read that some people do have that though - genuinely lovely, as I have two DCs myself and obviously would love it if they were close when they grew up, but I sure as hell won't pressure them if they aren't. That way tension lies!
I think a lot of people who are friends with their siblings have said that they don't live in each others pockets, which I think is maybe something to do with it. There are some who do enjoy a good relationship and do see an awful lot of each other, but I think most of the people who have said they like their siblings don't see too much of them... But maybe I'm wrong about that. I haven't sat down and counted or anything!
The sibling I'm closer to, I do actually speak to every day, but I think that's because we are both SAHPs with similar aged DCs. When we go back to work, we probably won't talk so much, which will be sad, but fine and part of life.
Also interesting that some people who don't have any or a particularly close relationship with their siblings are happy enough with that as long as they don't have to see them! I can relate to that tbh. I feel the same about one sibling and also some of our more distant relatives - I only see them at funerals these days and it works perfectly, although growing up, I always thought we'd stay in touch more. I lost one of my parents fairly young, so I think that side of the family naturally drifted away a bit.