travelling would be easier if tip culture did not vary so much from country to country.
Yes, but experiencing different culture (including tipping) is half the reason to travel.

I agree on the value of learning about different cultures. But I don't think knowing tipping culture differences is culturally or humanly particularly enriching, though. But maybe I fail in seeing the implications of that.
Not so much in knowing
what the tipping culture is, but
why. And, just as interesting, when different cultures intersect, how they approach things. In one, a "normal" American tip is considered extravagantly patronizing, while in others, it's more "let's get all the money we can from this idiot."