Traditional CX bikes were meant for bursts of short, aggressive riding and portaging by hand over obstacles. They're not meant for long distance riding in the way of a road bike.
Modern gravel road bikes/adventure bikes on the other hand, are built around endurance road bike geometry and they're comfortable for all-day rides on multi-terrain.
I would leave a CX bike for CX pursuits and a role as a townie bike, not to ride a long distance.