I can see where you're coming from, and agree, but ISPs in Australia providing services on the National Broadband Network NBN will almost always describe this as a modem router.
It's not uncommon, right or wrong, even Verisign USA describe a modem vs router thus: "The modem is responsible for sending and receiving signals from the ISP, while the router disperses the signal to devices on the network"
So, this doesn't exclusively modulate and demodulate (mo-dem) an analog to digital signal in this case, and 100% it doesn't have the physical hardware to do so, but it is nonetheless required to negotiate ('modulate'?) the internet connection with an ISP, albeit software-defined through digital PPP Ethernet protocols.
All this is a bit off topic, but I hope the OP (or others) may better define the internet service needed, and may determine if this device may be suitable for their requirements.
I'm glad it includes openwrt support for later down the track. It's one of the few AX devices with such support and I chose it specifically for this reason!
Seconded on Cockpit project w File Sharing.
Probably not best practice, but it's possible to install it on the PVE host itself since its ZFS manager and Identity manager plugins and other features fills some gaps in what Proxmox doesn't do (or would have to drop to CLI to do).
Also recommend RClone in a systemd can take care of various file movements, syncs and backup tasks you may need against the host, vdumps or SMB file shares.