A debatable point, I postulate that if it no value then there would have never been a second block and if it ever dropped to zero value then there would never be another block.

Of course for that to happen something huge like QC that breaks the algo and manages to create enough free coins and dump the market to nothing while also hiding that fact so that a different algo could nt be forked in. It would take the planning of a computing super power nation state (or a combination of them). And I would argue that none would ever do so as it is easier and more effective to co-op the chain.