It’s only gone from YAML. UI setup is still possible for the System Monitor.
This is an on-going process. Many YAML integrations will be moved to the UI. A lot will remain as YAML. Specifics are detailed here: The future of YAML - Home Assistant
Now you got CPU temperature provided by System Monitor, so the CPU temp command_line sensor may be excluded/commented in your config.
In some cases CPU temp is not provided by System Monitor (depends on a hardware probably), then you have to use command_line (like you did).
and one of them is called Binary Sensor (like how I had it named in the .yaml file). That .yaml file is completely commented out in configuration.yaml now, so I was wonder why the name still existed. I was using that sensor to give me this guage:
Looking at the documentation - looks like I can use it now for knowing when my cell phone is not pinging (i.e. Not At Home).
Now to figure out if I still need these Heating and AC tracking sensors.
Yeup - know from back when I started with HA - the AMD CPU on this HP T620 ThinClient would not show - after some conversations with the developers, and sending lots of logs and stuff - they got it working with those lines in the .yaml for CPU_Temp.