Why can't non-institutional actors achieve the same level of privacy? Seems like it would be much, much easier for smaller actors since they are dealing in much smaller amounts..
Non-institutional actors are transacting over an immutable public ledger. Institutional actors are transacting via backchannels. In other words: the cryptocurrency transaction space is "schizophrenic": the traffic that supports high valuations is not settled on the chain itself, but via gentlemen's agreements. Non-institutional actors could do the same thing (and get the same privacy), but then it's just normal money laundering instead of "decentralized finance."
As in, they are keeping funds on centralized exchanges? Users can do the exact same thing if they want, not sure I get your point.
I guess I'm not sure how you get from that to privacy only being achievable by institutions?
The only points being made are that (1) virtually nobody actually wants their entire life's transactions recorded on an immutable public ledger, and (2) the people whose economic activity currently backs the speculate value of these coins play by a different rulebook entirely.
I guess this is where I don't know what you mean, specifically