Now do the necessary steps to see how many it takes to multiply large numbers, let's say 1'785'375 * 7'367'594, in one method vs. the other and then comeback and tell me again if you'll ever use anything else than lattice one.
If I needed to multiply a pair of seven digit numbers, I would probably approximate them by dropping all but, say, the two most significant digits of each. If that amount of wrongness is a big problem, then I probably should have used a calculator in the first place.
I hate when I'm trying to figure out how many guests my friend's wedding venue will fit with 1,785,375 to a table and 7,367,594 tables available, Common Core fails me and I've forgotten how to lattice ;)