I don’t have a Samsung Connect, but from what I read, it’s not a router. It acts as a mesh wireless access point system. Wireless access points are different than routers in that they don’t have router functionality such as routing traffic and handing out IPs. AFAIK, you’ll still need a separate router.
My understanding at that time was that the SmartThings Connect Home subhubs (a since discontinued model) Could not be used as ethernet access points.
I may have been wrong about that, but it doesn’t seem worth resurrecting a 10 month old thread for.
To go back to the OP’s original question, both the Samsung Connect Home model and the Samsung SmartThings WiFi Mesh router with Plume are WiFi routers. The piece that they are missing is a modem. So unlike some gateway models, it’s not an all in one unit. It can create a Wi-Fi network, but not connect to the Internet. So you need a separate modem for that.
As to whether you can connect a network switch to one of the subhubs of the current model, I have no idea. LOL!