I'd agree if you have a house big enough to have a playroom, and have open space close by, it's probably easy enough.
Our lawn is kinda a tiny, tiny, wildflower meadow, ie it's not cut much. The bees love the Clover.
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).
It's almost like sweeping statements such as "no one should have a lawn" need modifiers. ;o)
I'd guess grass is still better environmentally than gravel; so long as you don't over tend it (and our mower was rescued from the dump).
Have fun.
You have to mow it. You have to mow it every week. You have to mow it every week even if you're tired, or sick, or it's hot, or it's cold, or it's rainy, or your friends are playing a game, or you had a sleepover. No excuses, no exceptions. You can't mow it too early in the morning, or too late in the evening. You can't stop halfway through and do the rest later (back yard/front yard perhaps, but not half of the front yard). The grass does not care what your reasons are. It just cares that you didn't mow it. If you don't, it punishes you. Sometimes the neighbors do, too.
In theory they understand this, in practice there are plenty of other activities that result in a litany of renegotiations. Grass. Doesn't. Care.
I have a kid and I'm grateful we gave up our lawn. She plants in the spring, harvests, cooks, and preserves with us. She's excited to make pickles, jam, squash, pumpkins, corn, etc from things she's grown and tended to. She even got to pick out some of the flowers and make her own little square.
Watching her step out to grab some blueberries, raspberries, or strawberries is one of the best feelings in the world.
We read seed catalogs together in the winters and plan what we could grow (Ooh, what if we grew purple cauliflower? Or rhubarb for pie!)