~$800M of SPY traded in the closing 1 minute candle today, ~$40B in total. That’s a single ETF.

$3B is peanuts compared to real equity and bond markets.

That's a straw-man (or True Scotsman?) argument. You're putting up BTC against the most traded ETF in the world, and claiming that BTC has no liquidity because the volume is just 7% of that?

There's nowhere in the world where $3B daily volume can be called "negligible".