Without bars, we couldn't count. Can you imagine counting a twelve bar 4/4 blues 1, 2, 3,...,48? Isn't 1,2,3,4 | 1,2,3,4 | Etc. much better?

What about 11/16 time? 1,2,3,1,2,3,1,2,3,1,2 | 1,2,3,1,2,3,1,2,3,1,2 is a lot easier than 1,2,3,...,11, and it tells you where to place the accents. Try it.