Cure Nyammy's henshin is gorgeous - it's animated by Itaoka after all and I love the style they went with for the cat duo, it's super cool and original!
However, I wouldn't call the current Cure season any good either. I haven't been following it but the first 2 duo henshin were super lackluster.
In a sense they are kinda those of Cosmos but with a little more budget. It's well animated but over all, it's bland, uninteresting and quite frankly boring and repetitive.
We are far behind the times when Toei was making really good Precure, the last really good one being Go Princess; be it on the animation, characters, story, aesthetic etc.
It's not for no reason that Yes 5 is still so popular in Japan.
There have been some good seasons but the writing and tone is not as captivating as from the Go Princess era.
Toei generally goes for a very lackluster, kidified season (Delicious, Wonderful) and continues with a more polished, less safer one (Hirogaru) so next year's Precure is logically gonna be something to look forward to.
Also, considering Mahou Tsukai 2 has been in production for the last 2 years and it's confirmed to be on a night block, Toei's probably put most of it's talents on that series.
At this point we sound like a broken record but Crystal III was actually a polished and decent budgeted season as well as the best this adaptation would have ever looked.
Sailor Moon wouldn't have ever gotten a higher budget, especially not under Toei.
And we can see that they were really gunning hard for Sailor Moon to be a 'Otona Magical Girl', Usagi was the spokes-lady for OL with all of those collaborations.
However, for whatever reason, there have been some behind the scene conflicts which led to Etermos.
Regardless, we do not have the viewership of Crystal III.
If Sailor Moon didn't meet the requirements of Toei (not the same thing as whether it made enough/good money), and the Japanese public didn't respond to it, you can't blame Toei to not want to care as much for it.
Even if Sailor Moon is in the Top 4 of Toei's production, it still remains the less performing of ALL of their IPs.
Is Toei responsible for how bad of a reboot this is? Yes
Is Toei responsible for not caring about Sailor Moon because it's not as popular and deserving as it's other series? NO.
Sailor Moon is not Toei's baby. They do not have a duty to nuture the legacy of Sailor Moon.
Not to mention having to share a major share of profits with Takeuchi as well as having to meet her very strict conditions, why would they even bother with all this much trouble when they can easily get as much money if not more from their very own Otona Magical Girl?
At the end of the day, Toei is a company that works to make money.
It doesn't produce anime for the artistic value of it, for the sake of the fans or for whatever other 'responsibility' they might hold.
There might also have been contract obligations just like with what happened with Saintia Sho which led Toei to quickly produce Etermos to make as much money they could.