I think the issue isn’t that shorting and other functions exist, but that these aren’t carried out by most retail investors. So frequently financial firms will benefit on this functionality using the base accounts of their customers.
So the introduction of this intermediation creates value possibility for large firms away from individuals.
Shorting is available to pretty much everyone now, especially with Robinhood et al and easy access to options markets (of course most people don’t understand vol and probably shouldn’t trade options). But it’s been easy to short even on the legacy brokers for as long as I can remember (a decade plus).
The issue with shorting is that you have theoretically unlimited downside which means greater risk and familiarity with concepts like margining. That is often outside the grasp of the average retail investor.
So the introduction of this intermediation creates value possibility for large firms away from individuals.