The only reason to believe it would be better with less people is delusional fantasy.
The problem isn't population, it's policy.
Cities aren't generally overcrowded because they have no other choice, they're overcrowded because cities typically offer the best opportunities. If the population were to drop three quarters overnight, people would flock to cities.
Land use is also about want, not need. We don't have to do it to sustain our population and its growth, it's just the cheapest (re: most profitable) option.
So... 100-400 episode seasons aired four times a week year round?