We could solve a lot of our problems right now if people were prepared to change how they live and accept a decent amount more responsibility (e.g. sort waste by hand, etc.). Scaling up problems typically hasn't helped, and you get novel issues at large scale (e.g. parasites and diseases thrive due to monoculture in huge farms). As Bill Burr noted, we could all drive tanks to work if there weren't as many of us. It's cynical, but there's more room for largesse at small scale.