I think the biggest reason people subscribe to hypersubs is just like proximity/alignment/support of the creator

Like you see your friend launch a hypersub, yeah of course you're gonna put a few months down on it

don't think ppl really have cared much about getting "value" back

This has been partially my experience but not entirely. 

Definitely a subset of people who subscribe because they want some sort of special treatment/etc.

But a lot of people stay for value too. Especially artists who I spend a great deal of time trying to help promote.