The only arguments against fake grass are that it doesn't look nice, and it isn't made from sustainable materials. The arguments for fake grass include that it is low maintenance (negating some of the environmental impact), and that it is much better for people with accessibility needs.
Meanwhile, grass lawns require lots if maintenance (not good at all for the environment), aren't good for people with accessibility needs, and look boring and unvaried. Meanwhile the upside for a grass lawn is it looks traditional. To that I say, screw tradition. Grow clover, wildflowers, moss, and edible plants in your yard. These NIMBY brit-karens fan fuck off