Look into commercial/digital signage displays from NEC, LG or Samsung - they're designed for pure display functionality with excellent panels, multiple inputs, and zero smart features.

Increasingly zero smart features isn't one of the features of commercial displays. For instance, a lot of Samsungs want (but not require, as far as I know) you to use their VXT content and remote management system, including a mobile app to control calibration and they still run Tizen, like their consumer TVs. LG appears to be similar. NEC might be better about this by making the smarts an optional module. Hopefully all will be less onerous in their implementation of twiddling you with their smart features, but it is hard to get away from even in commercial displays now.