Using physical metals as the base unit of account and settlement (Exter's Pyramid) allows you to remove all middlemen and if you would like some other type of convenience, you can then build a centralized system on top of it.
So how would build a centralized system on top of metal without an enormous amount of counter-party risk? How would you guarantee who held what? Goldmoney.com is currently already doing it, but you have to fully trust that they secure your metal and will deliver it in full on demand. HUGE counter-party risk.
There is no difference whatsoever in practice between metals and bitcoin in that case. For instance, for bitcoin to have any market penetration in the upper middle class of the world, you would need around 8 MB blocks, then on-chain transactions would still only be economical for something like transactions of $10k in value. This means you would have, say $100k in savings and transfer $10k at a time onto a centralized BTC debit card or something. With metals you would do the exact same thing, move small amounts at a time onto a more centralized system if you need the convenience.
Do you see now why bitcoin doesn't actually solve any problem whatsoever? lol. It just makes the base settlement layer of your system less sound than precious metals and introduces middlemen where middlemen shouldn't exist. This is why legacy banking shills like Larry Summers and Ben Bernanke support bitcoin, because it allows them to insert themselves as middlemen where you should be immune to them.