>When actual broker-dealers (like TD Ameritrade, ETrade etc) start trading tokenized securities offerings, it will be extremely advantageous because they have much more robust infrastructure and trillions of dollars of assets under management already.

Maybe. But maybe in the long run, the regulated industry, as encumbered by regulatory friction as it is (e.g. $10 per trade), is a dinosaur, and will be thoroughly eclipsed by this new unregistered blockchain token market with its nearly frictionless transactions.