We are at a moment where we're trying to figure out how to design good interfaces, but very soon after that the moment of "okay, now let's start selling with them" will come and that's really what we're going to be left with.
In that regard, things like adblockers which now a days can be used to mitigate some of these defects you talk about are probably going to be much more difficult to implement in a chat-app interface. What are we going to do when we ask an agent for something and it responds with an ad rather than the relevant information we're seeking? It seems to me like it's going to be even more difficult to be in control for the user.