[zAy0LfpBZLC8mAC]

Well, yes and no.

Apart from allowing you to find someone to trade with, validating the actual trade/settling the trade is an important part of an exchange as well, and those at least in principle could be solved using bitcoin-based technology.

And also, bitcoin at least partially could "solve" the problem by just not requiring the use of an exchange anymore once it has sufficient adoption. After all, most people don't directly need an exchange in order to use their local currency either.

And finally, there are suggestions how an exchange could prove its BTC liquidity using the bitcoin system, which would also solve at least part of the abuse potential of a centralized institution.

But yeah, it's not fully solved (yet?) and I simplified things a bit, but I think nothing that has any impact on my argument.