It's a cute little optimization puzzle they made for people to solve, with lawn mowing as a graphical hook to make the problem more approachable and fun. Similarly, my kids have a physical logic puzzle where the theme is putting plastic cats into plastic boxes, but it's not supposed to be training for actually optimizing cat packaging.

How is this any more or less valid a use of time vs. mini-golf?

(The "real" analogous problems are things like optimizing factories or delivery routes, and the way they are solved is by programming a computer to, but this is a toy version.)