Many scientific measurements are entirely contextual. e.g. What is 0 V? Ground? Is ground across the globe always at the same potential? Nope. What's ground on a space station? Ground potential is whatever we want it to be. You don't need to define what ground potential is in, say, a computer, relative to some global standard for things to work.

How about velocity? What's 0 m/s? What does it mean to be absolutely still? All motion is relative, and being still is entirely a matter of perspective. You might be sitting still on a train, but traveling very quickly relative to a cow standing still while you blow by.

Bels are a relative measure that confuse some because they pop up in different contexts that seem unrelated. However, they are useful when dealing with quantities for which most pertinent relationships are exponential. e.g. They work for sound because humans perceive exponential increases in volume in a linear fashion. Something that is 3dB louder is twice as loud in terms of pressure levels, but we only perceive it as a little bit louder. Sound pressure levels are both relative measures and an attempt to reflect human perception . That makes them, necessarily, a bit odd.

None of these other examples are contextual in the same way.