A lot of big insurers have never sold non-employer plans in most states. So it’s a little misleading to say they’re “sitting out” unless there’s some indication that they were expected to get in in the first place. IIRC, Cigna for example was never really expected to participate in the Exchanges. Blue Cross bid for some of them.
According to the ASPE report, on average, individuals and families will have 53 qualified health plans to choose from in their rating area, from 8 different carriers. That seems like a reasonable variety, although they could be systematically inferior, as you suggest (though obviously not along any of the variables that are regulated by the exchanges).
As for the provider networks, I’ve seen that claim made anecdotally, but I’ve not seen any comprehensive comparison. It certainly wouldn’t shock me if the plans have smaller networks on average. Of course, in order to reach the conclusion that they are “products that are also worse than expected,” one would have to examine more than that aspect of the insurance policies.