If I recall the new soccer stadiums they build now have a concert stage built in and they play high school football in it as well.
The stadiums owned by AEG have stages built-in, which was a sticking point with Red Bull and why they're going to build Red Bull Park
without any interference from AEG.
And yeah, soccer-specific stadiums often host other events around the year. Concerts, the X-Games (in LA), and high school football playoffs (in Dallas), specifically.
Maybe with a stadium that's not way too big for a crowd of 15,000, KC can generate an atmosphere like this
rather than being one of the most depressing places to watch a game in the league. Section 8 did a good job at Soldier Field before Toyota Park was built, and DC fans do an amazing job at RFK, but those are definitely exceptions.
That being said, Portland's Timbers Army is ****ing amazing for a USL-1 side: