I never really understand why you'd rather have one of these over just enabling "hotspot" on your phone. Ethernet is the only reason I can think of
If you have an Android phone you can connect a USB-C to Ethernet dongle (the same one as you have for your laptop) and get tethering via Ethernet out of it. It works really well.
we take a webcam to keep eye on dogs sometimes. I use a travel router for that
What if you want your kid(s) and/or partner(s) to stay connected after you leave the hotel room with your phone?
What if you want to use the hotel's internet connection instead of your roaming data?
What if you want to use wireguard or tailscale to funnel all traffic through your home network?
What if you want to enable your family's devices to connect to your self-hosted services?