Faiz is Faiz. It's the whole package, not just the middle or the start.

Then Den-O too) Plus, Revice doesn't even use the Ryuki vicestamp.

I mean, how can you understand from the first episode or even from the first ten that the show is similar to Faiz? Even if Rider's belt is stolen, it might just be a light reference. Was Kiva very similar to Faiz? Or Donbrothers? Well, this is not a comedy series (and then, are Den-O and Fourze really that much alike?) or Amazons 18+, where they immediately let you know what awaits you. Therefore, even if the entire film crew says that the show will be similar to Faiz, I will not believe them until I am convinced myself. Trite because it might not work.

I think Inoue's works are all pretty similar in tone and the tropes he uses. It's not like Faiz is all teeth and death either, there's a lot of comedy as well, like how Build uses comedy to contrast its very drama-heavy plot. Amazons is more like a PG-13 by Japanese standards though. For works that have an inconsistent tone, Hibiki and EX-Aid comes to mind for me. Even Agito was a little choppy.

people trying to link Heisei and Reiwa series < The belt number theory

and that says a lot 8)

Yes, but for some reason, fans want Faiz, and not his other series. Plus, I have a guess that when making Kiva, they just wanted to take the best from Faiz and Den-O, mix it up, add a chic visual and get a masterpiece. Slightly failed, although, for me, the result is not bad.
Otherwise, I agree, except for Hibiki's tone jumps ... Personally, I think that the reason is that in this show we are not shown a story with a beginning, an end and an idea that needs to be conveyed, but a segment of life. And everything happens in life.

Yeah, I don't think anyone is seriously trying to tie them up. Rather, you just want to see something similar to your favorite season again, which is moving away (well, if a new favorite does not appear). And, again, I am convinced that even if the show is a complete double of the same Faiz, it will not be clear from the first episode. In addition, the scriptwriters themselves hint to us which seasons of Reiwa and Heisei are connected. 01 with Ex-Aid (by the way, I'm the only one who feels bad that we lost Vulcan and the entire MetsubouJinrai, getting Dan Kuroto in return?), and Saber with Ghost.

The whole linking hesei and reiwa series thing is honestly pretty goofy to me. Like I wouldn't be shocked if there was some effort on toei's part to create some vague similarities, but rider generally has a lot of tropes and idea recycling, and the shows are so long that I think you could pretty easily draw comparisons between any two random shows....

Like I think the most compelling one is "saber and ryuki" and that's literally just that the main character is a red dragon and a knight, and there's a lot of riders and that's like literally all the substantial similarities (and calling even those "Susbatantial" is being generous lol). It feels very likely it was totally coincidental since Saber is story book themed so it's not shocking to me in the least that the main character is themed after dragon and knight stories, that was always going to be the obvious route for that theme

For the sake of demonstration, here are some connections of varying quality between Heisei Phase 1 and Heisei Phase 2:

Kiva and Zi-O: King Monster
Kabuto and Drive: I am Speed
Blade and Gaim: He who fights monsters should see to it that-- uh...
Den-O and Ghost: Call forth the spirits for power
Ryuki and Ex-Aid: "It's a dangerous game we're playing..."
W and Faiz: using gadgets against an evil organization, and someone related to said organization made the gadgets
Kuuga and Wizard: both the main hero and a notable antagonist are connected to a magic stone
OOO and Decade: I like long walks on the beach and honestly just traveling in general
Fourze and Hibiki: learning from others grants the greatest of powers
Agito and Build: What should be done with the power to create and destroy?

those are some mighty big stretches we're going with there