Nest locks users out of their own data

(I’m in the US.)

Does anyone use Radio Thermostat (CT50/CT80) as an alternative to Nest? What are the alternatives with local AIP access? Protocol (Wi-Fi, Zigbee, Z-Wave, etc.) does not matter to me.

It seems to me that anything that looks very modern and sleek-looking such as Nest or Ecobee would require Internet access, so it makes sense that I should not care for the modern looks when choosing a thermostat; however, that can be worked around with an in-wall tablet with a modern thermostat interface that connects to Home Assistant.