I think blood is important, but that doesn't mean you owe your family anything or have to sacrifice anything to keep in contact with them if they've mistreated you.
I think if your blood relatives didn't raise you, then it probably means very little beyond a health/medical thing. However, it means a lot to a lot of people on some emotional level, it's why people who are adopted or whatever the situation is wants to meet their biological parents most of the time. So when I say "it probably means very little", I mean in a practical sense like a family structure.
Family is obviously a chosen thing regardless (as in it's hard to say it's X thing, most people will agree "it depends on the person"), people choose blood and others choose chosen families. Because it's a choice either way, I guess it comes down to personal preference.
So for me "objectively" chosen families is "most important" because in a lot of ways that's what someone is doing even if they pick someone related by blood, but my personal preference is it depends on who raised you more than anything else. Choosing family as an adult is a lot different than being a kid, and as an adult, family actually means a lot less than people might assume (because you have the option to be independent, unless you have children, and you can usually pick who you marry and/or have children with).