

Meter was easiest for me because it’s essentially a yard (when eyeballing).
Liters are easy because the soft drink industry picked up on it decades ago as a way to get people to drink more soda. You’d buy cans and 6-packs, but nobody bought a gallon of soda. But they would, it turns out, buy a liter of soda, and as we got more obese as a nation, 2 liters. Liters of consumer drinks are really common, and so easy to visualize.
Huh. I don’t really hear any units of length anymore, now that I think about it. Even the doctor measures my height in inches, not feet+inches.
I honestly don’t know. I don’t hear “meters” used at all, but the first thing that comes to mind about “yards” is the 2000 movie The Whole Nine Yards.
US football still uses yards, doesn’t it? I don’t watch football either. But I just checked a random football stats website, and it still uses yards to measure pro football stats, so… yes, I guess. A lot of Americans still uses “yards.”