Originally Posted by chas58

It depends what you mean by competitive. Certainly not in CAT1-2. But CX often is more about having fun on whatever you are riding, rather than being like a road bike race.

Some mis-information here from people who read a lot but don’t ride CX.
CX bikes used to be the all around bike. Now Gravel is in fashion (for good reason I would say). This has allowed CX bikes to get more focused and racy – so there is no longer a need for a CX bike with fender and rack mounts, nor as much a need for a non race CX bike. At the same time, they have adopted a lot from gravel racing. CX bikes have gone through a lot of changes recently.
You can of course use a gravel bike for CX, but they are going to be crap (in comparison) in the tight hairpin turns, in rapid acceleration, in climbing, and of course there pedal strike and sloppy steering. Then again, CX is casual fun, run what ya brung – so we have people ride just about anything. My favorite was a 50 year old Schwinn Tandem. Worked well when you team mates are handing you whiskey shots on ever lap. ;-)