Great Article Investigating this, must say I have similar questions myself. There should be some investors that back the people behind Cardano this early days. Also the fact that there will be no tokens issued ever is new to me and would make sense for the scarcity aspect.

However as things stand I am not aware of any use cases of the token, I think the only thing you can do with it now is hodl.. but it's unclear to me what you are holding as you are definetly not holding shares into a company or anything like that as InputOutput is a bigger entity that also support the ETC project.