Nobody can deny that MMA is the reason why BJJ became popular at first. Royce Gracie shocked the world in the early 90s by beating a lot of dudes using submissions. However, nowadays it is very common for people to just enjoy the sport for what it is, even with no interest in fighting MMA.
The same applies for boxing, wrestling, muay thai, etc.
But what if you do want do venture into the cage? Do you have to train any differently?
The answer is most certainly yes. Regardless of what it is you train, preparing for MMA requires a different approach to the craft. There are a lot of positions in all of the sports I just listed that are simply not optimal for the cage, and should be practiced accordingly.
The best athletes for each sport, move in ways that are optimal for their specific sport. So remember, while you can train everything individually, putting it all together and picking and choosing techniques is the hard part.
now a highlight video of George St. Pierre, arguably the best athlete ever to fight in MMA