I'd be more optimistic about the ability to deliver an approximate equivalent if there were someone paying for them to do so(the economics of ordinary satellite launches seem to favor fitting within what a given delivery vehicle can handle, rather than bolting things together, so it's not 100% assured; but seems likely); but less clear on replicating the incentive structure.
It's not that the ISS is totally useless; but it currently justifies an awful lot of launches, including manned, more or less by being there. Gotta launch that crew lest the ISS be empty which would be bad because reasons, and have to launch those supplies because there's a crew on the ISS. They do find scientific things to shove into modules; but the arrangement is such that no project is ever called on to justify the ISS, which is just sort of assumed.
Short of the feds just paying some contractors and calling it a 'private' ISS replacement; it's less clear that there's much private sector incentive to build an ISS-like; judging by quite vigorous stream of privately justified satellites designed to not be bolted together and the relative absence of jostling for ISS experiment space. If it were worth that much we'd presumably be up to our eyes in sordid stories of people pulling lobbying stunts to try to exploit it on the cheap through regulatory capture; but we aren't really.