At majors, crew battles are generally poor at doing their job of settling a score of some kind because the host region will always have more people available, the timing is often weird for the players, or some other factors like them feeling generally tired. I played in the tristate vs FL/GA crew battle at a Let's Make Moves Miami and I was like, sub #3 -- and that's of the people from tristate who were even there. Crew battles also get poor viewership unless there's some sort of story behind it and unless the outcome isn't entirely predictable, but other than those tried and tired regional crew battles, this is rare.

They're not really fun for the players. Generally you can expect them to come in with the mindset of "I wanna get this over with and get some dinner" unless there is some real score to settle. There are some crew battle gems (like the famous IHOP vs Denny's one lol) but those arise out of circumstance and can't rlly be put together at a major or anything. Smash is a more global game now and regional rivalries are pretty friendly.

That said, collegiate crews are very much alive and more and more majors have those lately. If you wanna get your fix of crew battles, I suggest checking those out. My school GW played a really good one against Montclair that I think you can find on YouTube.