[Kurona]

It's due to the slow process of getting SHFs out, combined with the sheer number of suits Tokusatsu puts out these days.

Back in the days of, say, Fourze; there were 7 main suits in-show, plus 3 movie-exclusive ones and the bikes. Especially with how fast SHF put stuff out in the early 2010s this also gave them room to do more stuff like module sets and villains and even the space suit; and sure enough, we saw almost everything Fourze released in 2012 with only a module set, a few villains and the late movie suits done in the following year.

Fast forward to recent stuff and oh boy. Counting all the TV series riders and only the main upgrades, Zero-One has more Riders alone than Fourze had suits; at 9 riders plus 11 upgrade suits. This isn't even counting the movie stuff either -- that adds on another 10 (though I don't think we'll get Abaddon and Lucifer). Zero-One prioritised doing Izu as well, and is now doing the bike. And then when you consider that this series wasn't exceptional for this, but in fact was the norm among modern Riders, so they're constantly juggling playing catch-up with the previous series and then there's when they get onto the next series too...

Basically there's no way stuff can come out anywhere near as fast these days. Zero-One has almost 30 suits to cover, and so does pretty much every other Rider season around it. It's only natural it's taking them a while to get to the end-series form