I find this really interesting (like many things Canip says), and I wonder why it isn't so. Why doesn't Canon make a bold move and leaves everyone in awe with a 10x42 L IS PLUS with improved ergonomics and weight/size. I'm sure Canon has a complex product development process, a pipeline where many actors are involved, and it is not unlikely that they read criticisms here and there (or carry out product satisfaction surveys of some sort). And yet, for example, their new 32 mm line up has grown bigger and heavier than their predecessor, and hasn't done much to address ergonomics (yes it has an improved IS interface, where you don't need to constantly press the IS, but it hasn't improved on eyecups, haptics, etc.).
On the other hand, I'm sure someone in the "big 3" knows what a 10x42 L IS is capable of, and the idea of putting some electronics on a piece of optics is nothing new to Z/L/S (they all have binoculars with range finders and other increasingly complex devices needing batteries). I guess developing something like what Canip says would take an awful lot of money where the return would not probably justify the investment in the first place. But, for example, take the Nikon 10x25 Stabilized. I have not seen it "in the flesh", let alone used it, but from pictures it looks almost just like your regular binoculars with central hinge, twist-up eyecups, etc. A proof that something can be done (better than what Canon has to offer on the ergonomics/usability department).
Said all that. I bought my first IS back in 2021. And, answering the title of this post, in these two years it has been (by far) my most used binoculars, and I've had at my disposal some very nice "premium (alpha)" (albeit from the previous generation), like EL-SV, UV-HD, FL, etc. Whenever I'm carrying an "alpha", I miss the mind-blowing power of my IS; whenever I carry my IS, I miss the alpha optical quality and ergonomics. However, from these two scenarios, 99 % of the times I choose to get the IS with its lesser optical quality and poorer ergonomics (probably the 10x42 L IS is a mix of both worlds, but I'm afraid I'm not attracted to the 10x42 because of weight/size).