Paddling pools and wrestling don't take a 1/5 acre lawn (not atypical suburban plot size). In my previous house, the back yard was heavily landscaped/hardscaped - patio, retaining wall, rocks and shrubs on the hill, etc. The front was lawn. Still plenty of room for my son to run around. And if he wanted more space, he went to the park around the corner.

There's also a substantial difference between a "natural" lawn, where clover and other plants are allowed vs the stereotypical "perfect" lawn (in the US) with a single grass species (and heavy application of herbicides and fertilizers).