Easily the most used bike.
But, I use it so I can ride from the house into the Peaks for a few hours at a time and keep fit. CX bike has definitely improved my Mtb fitness.
Don’t use the CX bike for rough stuff, see no point.
I’d have a road bike if it wasn’t for all the cars, so a CX bike for me is a safer option. I can go on the road and around the forest tracks, bridleways etc. Places I wouldn’t take the Mtb because I’d feel that was overkill.