The question that emerges now is how many binoculars do you need?
You can only use one at the time, that's for sure.
But since zoom binoculars are awful and handheld binoculars don't accept replaceable eyepieces, you only get one magnification at the time. So you might feel the need for at least one at 8x (most usual magnification) and another at a higher magnification.
And since even 42mm binoculars are somewhat big and heavy, you might need a smaller one, say 32mm. And a 20mm for those times when 32mm is big itself (dressed formally and without a briefcase).
If you do astronomy you might get into the hazardous giant territory, a real landmine for your wallet. Add sturdy tripods and sophisticated mounts here. Or simply IS binoculars of manageable apertures.
Do we need another for the theater? A Galilean type? And a close focus one? And a night glass?
Things can go out of hand. But if you are a birder, no. A 42mm and a backup 32mm will suffice. But there are so many objects there except birds to see.
I'm thinking, if somebody could build a waterproof binocular with precisely collimated clickstop zoom eyepieces that give 6, 5, 4 and 3mm exit pupils, with close focus at the lower magnification range and image stabilization for the greater magnifications, and a field of view of 56-68 degrees, that would weight significantly less than a ton, I might only need one 42mm. Maybe a 30mm too. I would pay 4000€ for that one, provided it would be of alpha quality (who else than Leica, Zeiss or Nikon could build that?) and so I wouldn't have much money left to buy other insignificant pairs then. Is it feasible? Yes, all the technology is available for years, we have good IS, zooms like the Leica Aspheric (we only need 2x), super light alloys, ultra small electronic chips and sensors and excellent optics, somebody has to combine these and invent a way to be perfectly collimated at every exit pupil/ magnification setting. Being insanely expensive will ensure that it wouldn't affect sales of other binocular lines, a few people would be able to afford it.