So how do I register foobar.com in such a way that everyone using DNS can access it without paying an organisation registered (directly or indirectly) with ICAN

So how do I register foobar.com in such a way that everyone using DNS can access it without paying an organisation registered (directly or indirectly) with ICANN? Filtering can be done - certain very-small-scale extensions can be done - and local DNS networks can be done - but if you take the goal of DNS-as-a-global-service as "provide globally unique, globally available name resolution", it very much is centralised.