The ideas of being independent and signed are inherently contradictory, and this contradiction is what makes indie hard to define. Its ephemerality gives it both a mystique and a resistance to criticism ― after all, you can’t critique what you can’t define. And thus, using the term indie is often a great marketing move. But it’s a problematic critical move.
However, as someone who knows he’s certainly privileged, I view my definition of indie as something that is also open for others to come behind me and use for free or have the ability to reuse and remix in a way that corporate interests or non-indie work wouldn’t. In a large sense, to me this means that while I may be privileged (whether that be socio-economically or even the time-encumbered), I’m helping to lower the cost and the burden for the less privileged who may come behind me to be able to do more, go further, or go faster.
In some sense too, as described, indie has such a nebulous definition. Often when I see it in a technology related space I really read it as “Open Sourced”.