Cross bike models are still out there from all of the usual manufacturers, but theya re made in much lower quantity than gravel bikes lately.
You can race a gravel bike in Cyclocross, and some do, but they will not be as quick handling as a cross bike
Cross is as big a sport as ever, but gravel has brought a bunch of new people in to the point that gravel riding is possibly bigger than Cross now
Bike Differences:
- A cross bike will have a higher bottom bracket and usually less clearance for wider tires
- A cross bile is stiff while a gravel bike is built with much more compliance to be comfortable for a much longer ride. A cross bike starts to get uncomfortable after an hour or two compared to a Gravel bike.
- Cross bikes are designed to be ridden at a near sprint continuously for 45 minutes while a gravel bike is meant to be ridden for events that last many hours and possibly at a pace a little below sprint level.
- Cross events often are won on bikes designed for lots of quick maneuvering to avoid obstacles and be most competitive while Gravel events tend to favor bikes that have a bit more laid back geometry and are designed for many hours in the saddle
- A gravel bike generally will have higher stack and a bit slacker steerer angle.
- You can find a lot of used good cross bikes but few good used gravel bikes because gravel bikes have really only been made in large quantities in the past several years.
- Since the gravel category has literally exploded in popularity you will find a lot more gravel bike models available than cross bike models
- Gravel bike models are evolving fast and change every few years while cross bikes have had relatively few chances in the past decade (except for new Shimano components)