Somehow I keep going in circles -.-
It's not about smart features... primarily it's due to the appearance, and I wonder whether most builders are satisfied with the standard (mandatory) ERR installation and the associated room controller on the wall (in terms of appearance).
The wired wall thermostats that look reasonably good are
Homematic IP wall thermostat with switching output 230V or 24V
Bosch Smart Home room thermostat 230 V
Both are SMART (hence probably the high price of ~ 80 EUR), which I do not use, however.
With 7 heating circuits, additional costs of 560 EUR for the appearance
Alternatively, with the option to place the wireless wall thermostat freely in the room or completely remove it when ERR is deactivated for about ~ 100 EUR more
Perhaps the builders are not currently bothered by this and I am making pointless considerations here.