People no longer socialize face to face so social gatherings are rare dating the old way is rare people are getting lazy and stupid by just letting machines do all the work watch what a teller does when their computer goes down that should prove the point
Concentration on too few species. For example, there used to be dozens of kinds of grain grown - now it is mostly corn, wheat and oats. And where there were dozens of varieties of each of these, it is today concentrated on the kinds that give the greatest yield. Which is fine if everything goes well, but if a plant virus comes along that attacks one of those super producers that everyone has planted, you don't have the biodiversity of the other lesser kinds of corn or whatever it is we're talking about, to develop a resistant strain. So the virus could simply wipe out all the corn, or the wheat or the oats in the world and we'd be in real trouble. Same with things like chickens - used to be dozens of different kinds, now there are pretty well nothing but leghorns and rhode island reds. And by feeding the chickens on chicken products they are simply reinforcing the probability of a disease that will wipe out most of the chickens. They do, actually, feed chickens with left over chicken parts after they are rendered down for food - and the chicken food contains feathers, skin, manure, bones, toe-nails - not a very healthy diet for a bird that nature intended to eat live bugs and seeds.