You don't need a CAQ to cover your local high school games, volunteer at marathons, etc. Frankly, 20-30% of a primary care practice is MSK chief complaint oriented anyway! If you feel comfortable in your MSK skills and management, you don't need a fellowship. Joint injections, sprains and strains, simple fracture care should be a standard for any FM physician.
For SM/MSK issues, I tell learners the difference between residency and fellowship training is the following: Both levels can diagnose conditions (infectious mono, spondylosis, COVID, rotator cuff tendinitis, etc) but a fellow trained doctor answers the question of when they can return back to sport.
Now what can a fellowship do for you. Maybe a better understanding of mechanics of injury, as well as return to play considerations. Also understanding what's the most beneficial for the patient regarding rehabilitation. Understanding exercise physiology and sports performance. Procedural comfort, use of US, etc.
Taking care of athletes college level and up tends to more of a fellowship trained physician. At some professional leagues, a CAQ and # of years in training is required. For example, to be a NBA team physician, you need 7 years post fellowship experience with high level athletes, and a CAQ is required. For Major League Soccer, it's 5 years (starting this year now fellowship experience is included, so really it's 4 years).
Hope this helps!