It's not impressive to conflate banks, ETFs, liquidation trusts etc that hold BTC on behalf of people.

Hell, even Microstrategy could see some of its reserves liquidated if it were for BTC's price to be under its target when their bonds expire. Legally speaking they aren't a bank, but essentially it's like they practice fractional reserve on behalf of its bond holders.

I don't think reserves play any significant role here. Compared to gold, much more of the supply is in reserves and also much more of the production gets placed directly in reserves. So I'd say bitcoin hasn't reached the state of being a reserve yet. We're far from it actually and likely will never be there. The fact that bitcoin is so liquid by design means its better as a transactional tool.