I guess you weren't paying attention when the writers and actors had to go on strike last year to fight to improve conditions that have made it increasingly difficult to make a living in the industry, due to the unwillingness of the studios to negotiate in good faith.
That had more to do with AI along with the affects of Character Like-ness when using a Digital Double & Monetization from Streaming + Residuals.
Since previous agreements didn't really cover those aspects.
And it's already been stated in this thread that both Saban and Toei have treated their actors pretty badly.
And things have changed from back then, otherwise, why would anybody keep going back?
The people who aren't fans of unions are usually the people in power. Which is why unions are necessary.
There are plenty of people outside of the Worker / Employer dynamic who don't like Unions, period.
A better opportunity would be a job where you don't get fired after a year, where you're eligible for raises and promotions.
Then go work a corporate Office Job & climb the ladder or a traditional 9-5 job.
Obviously, but in most shows there's at least a chance that the show will be successful and the actors will have steady work for years. And if the actors lose their jobs, it's because the shows failed. But here we're talking about a case where the franchises have been enduring successes for decades, but the actors don't get to share in that ongoing success.
The actors likeness is used during the year they are being promoted.
The actors likeness is imortalized in Tokusatsu history when ever they reference the past.
Just because the contract ends in one year isn't a bad thing.
There are other forms of employment other than expecting to stick with one company for long periods of time & expecting salary increases.
None of which is relevant to my point.
It affects monetization and opportunity to sign up for multiple roles simultaneously during a season.
While a classical physical actor has to be on set to generally do their jobs.
Which blocks a giant chunk of time.
There's a reason why there's a pay disparity; Seiyuu's & VA's offers more freedom to multi-book multiple roles per season.
Actors generally don't get to be in that many shows in one season of filming due to time commitments to a show.
The original Kamen Rider and Gorenger ran for about two years each in continuous production. The first five KR series had Akiji Kobayashi in common. Kenji Ohba of Space Sheriff Gavan had a semi-regular role in Space Sheriff Shaider, and Hiroshi Miyauchi was the team commander in both of the first two Rescue Heroes seasons.
And those were LONG time ago, when was the most recent occurance of that in Toei's Tokusatsu?
There have been plenty of low-budget shows that have kept their casts around for more than a year, although it's true that long-running shows often have a lot of cast turnover in later seasons to save money.
And a yearly cycle allows a fair trade in employment and pay for both parties.
If a actor is well liked and they want to come back, they might show up in cameos, guest spots, re-prise their roles, or get new roles.
Hiroya Matsumoto is so well loved that he's come back to Super Sentai multiple times.
He portrayed Tsubasa Ozu / Magi Yellow in
Magiranger
He portrayed Masato Jin / Beet Buster in
Go-Busters
He was a recurring background character known as Minato Hoshi in
Uchu Sentai Kyuranger
He had a Cameo in Kiramager as the Ice-Pop seller.
He's reprised his roles as Magi Yellow & Beet Buster multiple times already.
The only thing he hasn't done is show in Kamen Rider as a new character yet.
I suppose I can see the logic in having kids' shows start over from year to year rather than relying on a long history that the kids won't remember.
Especially when the audience cycles in and out constantly.
Although that's somewhat belied by how much long-running toku series embrace their history and legacy.
But those are usually one-off guest appearances, usually they aren't regulars on the new show.
Masahiro Inoue as Kadoya Tsukasa / Kamen Rider Decade usually shows up from time to time.
Which is always fun given his character and the chaos he causes.
Anniversary seasons like the current Gozyuger are all about reminiscence for the past.
But those who portray the characters seem to be AU interpretations of previous suits.
Which makes sense from a logistical stand point.
It also allows alot of creative freedom instead of having to depend on legacy characters along with their backstory.
The first decade of Ultraman's New Generation shows, despite nearly every season being set on a different parallel Earth, relied heavily on continuity, crossovers, and reuse of past Ultramen and kaiju from throughout the franchise's history.
Sorry, I don't follow Ultraman. That's one part of Toku I generally never got into.
I'm a Super Sentai / Kamen Rider / Toei guy generally.