The point is you don't have to be isolated, you just need to infect less than one other person if you're sick. You can hang out with your friends on the lawn, sitting a little further apart, you can be closer with a smaller number of people, you can go for walks outdoors, you can take out at the restaurant instead of eating in. You might choose to buy something online instead of going to the store.
Some of the people who are flaunting the rules aren't doing that because this is unworkable, they're doing it because they don't give a damn (well, some of them). I do realize some people are put in situations where they have no options (e.g. poor and works in a meet packing factory, that's not what I'm talking about here though that has solutions too).