Practice develops skills and training develops physical attributes, but there is obviously going to be some carryover which varies from sport to sport.
You can certainly train endurance as a general adaptation off the "field" and in the sports that very much mimic the training like running, triathlons, ect. they obviously do specific protocols that are different from the event performances themselves (intervals, hill training, ect.) that improve their performance better than just mock racing, but I think, from a practical coaching perspective, if a lot of sports skill demands (running plays, mat drills, ect.) put so much demand on the energy systems and the recovery capacities of an athlete that more specific training of endurance simply isn't worth it.
Also there is the question of how long an endurance adaption sticks around and how easy it is to maintain. It may very well be worth a soccer, tennis, or hockey athlete to do some intervals in their off season when maybe they do a bit less skill and team practice, but that practice may very well be enough to maintain any conditioning they gained beforehand whereas we know they will get weaker by the end of their season if they do not lift during it.