Show me a sustainable community where there is no money involved
You mean a large community I's warrant. I can think of several small communities, from kibbutzim, through amish villages and on to scientific communities in antarctica. I can't think of any larger groups though.
You think accounting doesen't happen in kibbutzs or amish communities? Whether its done with fiduciary media or good-will, its still a form of money involved in exchanges.
Well now we're getting philosophical and that's my favourite place, so I'm wondering, if the most successful blockchain in the future measures people's hourly workrate value, would you call that a currency? I'm imagining this currency could be built in a way where the only capital was the hours banked. So there would be no rich people, only people who were in demand at that moment. I think I might like that world, because a hard working plumber would be doing very well and an entrepreneur who didn't actually do any work would be doing badly. That seems like a very fair world to me. In fact, the way Bitcoin only measures accumulated wealth - because that's all gold and silver can do - might be short sighted. cryptocurrencies can measure things that metal can't and maybe they should? But would that be commerce? Would that be an economy?
An online community?
A community doesen't exist without transfer of value, either you pay for it out of pocket or your participation is being exploited to cover the costs. The socialization that happens there is information exchange, and this is exchange of value. Money is speech, to exclude it from a community is to restrict activities there. The purpose of nostr is uncensorability and this includes exchanging both tangible and intangible value.
Ok, but sometimes, you do want to restrict commercial activities and limit the exchange of values to contributions because value in the form of money can have a corrosive impact to the community (or the opposite depending on the case), because the fact that money can be used to other markets/communities, disturbs the focus of the community, let's say certain religious communities for example. Nostr is the case that commercial activity can have building effects for the community as long as it doesn't disturb other values like decentralisation for example, but money are not necessary to communities in general, although value does like you said...