You can go nuts with all of the high end optics out there. But the
truth is that high quality optical manufacture has trickled down to
the low end. 150 dollar binoculars, such as the rebadged Boat US
model

There are many things that go into quality commanding a higher price.
Optics is one. Design features of compactness and lighter weight while
still rugged is another. Shock resistance to being dropped and kicked?
Quality of sealing resistance to water is yet another. Resistant? How
much? Waterproof? What does that mean? A dunking or submerging for
several hours? A combination of the foregoing and more to be MilSpec?
Warranty of a couple years, a few, 5, 10, 30?

There are times when one really gets what one pays for. Now and for the
next 30 years through very harsh conditions and treatment. For 27 years
from now the MilSpec Steiners bought this Xmas will be replaced or
repaired under warranty.