I was thinking the same thing. Sure, this is better than a dongle in some ways, but is still an order of magnitude worse than the normal, flush-fitting expansion cards.
I do recall someone on the Framework subreddit saying that they carry a laptop around with them on a shop/factory floor, but mostly use wired ethernet when they stop and put it down on a workbench. Using a dongle wouldn't be great because it'd be something that would swing around unpredictably as he'd walk around a crowded room with lots of people and machines running. So in this case, this expansion card would probably be a useful step up from a dongle.
Regardless, a retractable "XJACK"[0] from the PCMCIA days might have been a better choice for this, if the hardware could be made "short" enough in that dimension. Downside there is of course fragility; I imagine they're easy to snap off.