Mitutoyo isn't a monopoly, not even close. Just because a company offers a product that is arguably just slightly better in one aspect than others does not make it a monopoly. (I say this with a 10 year old pair of harbor freight calipers on my desk that easily have a 2 year battery life with regular usage. Also, Dial Calipers.)

But to answer your question, must they? No. Do they tend to be bad? Yes. Does their behavior get worse over time? Typically.