If someone you really cared about blocked you, would you open another account to see how they’re doing?

That's only slightly weird and creepy. I guess like everything, "it depends". We'd have to talk about why the blocking, what kind of caring we're talking about. In general, I'd say if I cared about them at all, I'd respect their choice and clearly expressed desire not to be seen. If we're talking about caring including romantic sense, it would be a bad idea anyway as I wouldn't like what I see and it would take longer to get over. If we knew outside SW... well, I'd probably know how they're doing there. If they blocked me everywhere, and the reasons weren't otherwise made clear, I could imagine it for kind of closure I suppose.