I thought my comment made clear that liquidity
is a valid concept, and there
are valid times to bring it up -- just that most usages in these crises are by people who are throwing the term around hastily, without sufficient basis to isolate liquidity per se as "the problem".
If you agree with that, you're agreeing with my original comment, even and especially if you (correctly) believe that some problems are rightly called "liquidity crises".
As it turns out, FTX was not merely illiquid; no amount of time or low-interest loans would have coordinated the cash flows, and yet every apologist was happy to identify the core deficiency as one of "liquidity", rather than honestly say what they could reasonably have known, at the time, from their perspective: no money, with specifics to be filled in later.
>If a dealer owes a customer 500 BTC that they’re trying to withdraw today, they need liquid Bitcoins, not money.
Even granting the tenuous propositions that Bitcoin isn't a money nor could be purchased therewith, the right diagnosis still wouldn't be "they don't have enough liquidity", but rather "they don't have enough Bitcoin", since the former is specifically making a (bold, overconfident) assertion that the exchange is good for the money if only they could get a few loans. That assertion was false, and almost certainly lacked sufficient basis from its proponent even at the time.