I agree on the coffee machine. On the thermostat, not so much. We keep pretty irregular hours so being able to control the thermostat remotely, so the house isn’t being heated unnecessarily but is warm on our return, is useful.
It's smart and supports only Z-Wave, not WiFi. So something like a machine running Home Assistant must sit between it and the Internet. And then its up to you to decide how you want to do remote access, but WireGuard overlay networks (e.g. Netbird, Tailscale) basically solve that problem at home-user scale.
Reject all the WiFi-connected stuff, unless it's very user-centered and worst case you can upload your own firmware (e.g. a bunch of Shelly devices).
Plenty of houses are not well insulated though...