4P variants in general are less popular than they used to be, so I doubt anecdotal nor statistical data would be very accurate in determining that it should no longer be featured.
That being said, as a counterpoint, from my experience I’ve seen that others consider Collateral Worlds a “classic” with many easy to learn fairy pieces, most of which are variants on the knight.
1. Collateral worlds matches takes longer to form than some ffa variants, to a point where I waited for about 5 houra once for a game.
2. This game is really unpopular, albeit fun, kinda hard to sightread.
I may be wrong, but I just think collateral worlds is not deserving to be in featured, although I cannot deny it is extremely fun.