Great observation. There is more pressure on kids than in the past. My daughter (1st grade now) was assigned homework every day in kindergarten (age 5), at a regular public school in the US, albeit a small amount and she didn't seem to be too bothered by it. These do seem possibly above a 5-year-old's level, and potentially a turn-off if they don't latch on quickly.

However, I'm actually impressed that the Math curriculum at schools today is much less narrowly arithmetical, and much in the vein of some of the puzzles mentioned here, in particular the "sets" game.

These games are good ideas, I will definitely try them, at the same time if the kid just isn't into it, no need to give up on them going to college. Let them try something else, or just go outside and play.