The only two things in my smart home that require Internet access are my Ring doorbell and Nest thermostat. Everything else is either using non-WiFi RF (Z-wave or Zigbee) or uses WiFi but is fully controllable over the LAN and any optional cloud connectivity is disabled. Home Assistant on a Raspberry Pi automated and ties it all together.

Obviously that is a far cry from "plug it in, download an app, go through the setup, and it works" but it actually works and is rock solid.