Success wasn't guaranteed in the ancient world either. Even if you were cultivating crops, a drought you couldn't control could wipe out your crops. Or baddies could invade and steal your stuff and kill your people en masse.

Overall, we have way more security than the ancient world did. Droughts are still a problem as the western US has been seeing, but at least we're at a point today where it just means food prices go up rather than food vanishing entirely and requiring migration to other countries or something.

As for stress, largely European workers don't seem to feel the pressures that American workers do, which probably boils down to in part a mix of higher taxes leading to better safety nets as well as generally much more vacation time from work. Also politics in European countries generally isn't as polarized, though by no means is it perfect.