> capitalism + technology relies on unpaid, voluntary labour
You are falling into the breadtube trap of faulting capitalism for a societal issue that has nothing to do with it. Did capitalism force people to have productive hobbies? Would you prefer a system, other than capitalism, that prevented people from having productive hobbies?
Often times this error relies on the assumption that capitalism is what's preventing us from having an "idealized" version of communism that I've heard aptly described as Gay Luxury Space Communism, where anyone can do anything they want and society just magically pays for it. The problem is that GLSC isn't real, we'd need ~infinite resources to do it.
I personally blame this problem on charities. This is the type of problem that charities and foundations should solve but there is no safeguard for charity money actually going to the charity's cause of action, instead the moment you create any kind of non profit it transforms into Non Profit (inc) and all the money it received goes to (1) professional non-profit people for the job of raising money and redistributing it, (2) shuffled to other non-profits, (3) thinly disguised political activism.