my question about time?

Who in the world decided to use relative time? Using real time is perfectly fine, saying " I will be there in 20 minutes." but who decided it was okay to use relative timing? Like saying something like, " I will be there soon, or in a bit?" What the hell is soon and in a bit? How am I supposed to decipher that? When someone says soon to me, I think in minutes, but other people may take that as like 30 to an hour? I think if people are going to use relative time, it should all be universal, but that isn't possible so please just use exact time, it is so much more specific and easier to follow. I think the world might be a little more punctual if we don't use relative time. What do you say?