Multiple times I caught unexpected traffic and was able to block it piecewise including a lightbulb(!) that was sending mb packets of god knows what home.
If they were ethernet based I reckon some smart VLAN capable switches would be nice even at home to keep them out of each others business.
I moved home a few years ago and now I'm back with the ISP router and do often feel a little in the dark about what my network is doing!
https://support.frameo.com/hc/en-us/articles/23433637149842-...
Great gifts! (At least for those unconcerned with privacy or security, which is most people.)