Have you ever been to a Pride celebration? At my local one, there are more rainbows than anything else, but LOADS of people come decked out in various flags. More flags than FR implemented. By far. And there are quite a few floats in the parade that are themed more specifically than "rainbow pride" with flags to match. Trans, bi, lesbian, ace, heck there's even a group of older guys who make a Bear float every year.

Genuinely don't know where you got the idea that no one irl uses anything but the rainbow.

The CORPORATE crap only uses rainbows but everyone else is decked the fuck out.