At 51, becoming a noob Crit racer sounded electrifying - a challenge I would enjoy. Low cost of entry, fitness goals, competition goals, etc.
Then I watched some crit training, and noped my way right on out of there. A crash amongst all those racers and at those speeds would be terrifying, and possibly life changing in not good ways.
Gravel might happen, but I’m defo not on board for technical MTB or serious road racing. Audax/randonneuring/touring is much more likely. I have to keep my own personal goals for riding in mind: long term cardio health, weight control, and to support my tennis playing goals with better general fitness.