There is exactly one device on the market (that I have found) which seems to satisfy both sides of your interests here: a rotary dimmer by a somewhat obscure co

There is exactly one device on the market (that I have found) which seems to satisfy both sides of your interests here: a rotary dimmer by a somewhat obscure company called Martin Jerry which functions perfectly well as a dumb dimmer but also can be fully controlled as an iot device. The only downside (apart from the idiosyncratic physical knob design) is that it's a tuya platform device, but the manufacturer also markets a DIY version which is trivially flashable to open source tasmota or ES32Home, severing the connection to the mothership entirely while retaining all functionality.