There are so many of us now. Years ago, a man I was involved with complained about all the rules and regulations we have that we did not have in the past. I thought for a moment and responded that there are more of us now.
If just a few of us do some things, for example driving a car or defecating, we are unlikely to create much harm. But, the same action done by millions or billions of people can have catastrophic effects. This is the reason for regulations. Small acts by many produce large problems. There are many more of us than in the past.