I (briefly) used Eiffel in the 1990s. It had some of, if not the, worst tooling I've ever experienced for a programming language, and I've used COBOL compilers and MVS. A pretty nice language, but the software tool support initially was appalling.
I've only played with it 20+ years ago (a colleague was one of the few practitioner) and I don't remember EiffelStudio being _that_ terrible (it has a class browser that was not that much more horrible than Eclipse at the time) - but again, I only dabbled.
Now, I have to agree that the way they market the IDE as the best thing since bread came baked is kinda cringy..
Nice language, but seriously cursed by unusable tooling.