Is very different. With silver the shorts can do naked shorts and they can short more silver that actually exists because the COMEX sells more paper (contracts) than silver actually exits.
With Bitcoin is very different because longs withdraw the Bitcoins from exchanges to their wallets. So the Exchanges can’t really allow selling “paper Bitcoin”, because as soon as you allow selling enough of those and longs start to withdraw those paper Bitcoins from the exchange you are going to have a very heavy poblem if you don’t actually have Bitcoins to send.
With silver all is different, nobody reclaims their bars. They simply trust the silver is there. But it isn’t.