I think that's highly router dependent, but here's what I know.

Home Assistant can monitor some things via the UPnP/IGD integration [1]. If you're looking for something more advanced, you could look into SNMP Exporter [2] with a Prometheus + Grafana setup.

Another option is to set up a PiHole DNS server, which would both block ads for the local network, and give you DNS statistics on a per-device basis.

None of these can get to the level of granularity you can get with a pcap based tool like sniffnet, but they're a good start to network monitoring and should work with most home routers.

If you really want to go deep with your network monitoring, you could set up a more sophisticated using OPNSense/PFSense, but at that point I don't know what is and isn't possible as I have no experience with them.

[1] https://www.home-assistant.io/integrations/upnp/ [2] https://github.com/prometheus/snmp_exporter

I haven’t looked into Sniffnet much yet, but that probably depends what you run on your router. I use OPNsense, and the Zenarmor module does provide a whole bunch of useful info together with blocking capabilities. If you pay for a home-use license (I haven’t done this), can also get few more features like MitM with your own ssl certificate.

I'm also hoping for something like this! Bonus points if it had a "little snitch" type of operation where I could manually approve a matrix of (device x domain)

If your router supports port mirroring, you could offload this to another computer and mirror the WAN (or all the LAN) ports to that computer?

Depending on the router, you could log traffic from nftables to ulogd2 to some logging monitoring/shipping solution.

may be some DNS thing that you put in your router settings so all the traffic will go via proxy instead of direct ISP