I dunno if you can call Darling in the Franxx "less popular". At least in my circles it seems like a hugely popular work. A lot of people like it but I do consider it a bit of a waifu-trash anime, lol. So I didn't think it was as critically good writing as the other stuff I listed.
Kinznaiver is on the less popular side. As is BNA (Brand New Animal). The Tokusatsu community seems to like the SSSS.(Gridman/Dynazenon) anime, but arguably taking the Gridman name makes them more into Tokusatsu than the anime community anyway.
I had not heard of it until a month or two ago and yeah parts of it were definitely a bit cringe in the classic anime fashion but I liked the story and art style overall.
It's really hard to take an anime seriously when the girls outfits have butt handles. Darling in the Franxx got a lot of attention, but a lot of that was the meme crowd have a field day with it.
Not really everyone watches anime "seriously", you can watch them in a more light-hearted way. I'm a big fun of Kill la Kill really because of how silly and over the top it is, same for the second season of JoJo.
I actually liked KLK, even with the sometimes extreme levels of fanservice. I think the thing that made KLK work for me is how it was both a love letter and at the same time a direct challenge to the cosplay community.
Franxx however tossed me out when the robots are controlled by dry humping teenagers. There's a level of pandering at which I just couldn't take it anymore.
So you whine that Franxx has girl outfits with "butt handles", but then you like Kill la Kill, an anime that is so unapologetically about fan service. Actually funny.
Sorry to intrude into this discussion but... Franxx is a different level than Kill la Kill.
Have you seen the two shows? I know if you've only seen Kill la Kill where the BDSM "Disciplinary Captain" gets power from whipping himself, it sounds like things can't get any more hypersexualized, but somehow Franxx made it more awkward than Kill la Kill ever made it.
A big problem is that the romance / dating aspects of Darling in the Franxx were front and center, so the characters are supposed to have sexual attraction / romantic feelings for each other. So somehow all these sex-jokes just landed differently / in a totally different context than Kill la Kill's more joke-heavy style.
Somehow its different when the characters involved are "seriously" romantically involved with one another. Because now we as the audience are seriously considering the implications of these positions or sex-jokes / whatever.
I think you've expressed it perfectly. Both KLK and Franxx are fanservice heavy, but Franxx made it awkward and uncomfortable to watch. To be fair, there are some parts of KLK that go beyond as well, but they don't appear until later in the series. Franxx put it front and center in the first episode.
Kinznaiver is on the less popular side. As is BNA (Brand New Animal). The Tokusatsu community seems to like the SSSS.(Gridman/Dynazenon) anime, but arguably taking the Gridman name makes them more into Tokusatsu than the anime community anyway.