In metric countries, it tends to be in multiples of ten (180, 190, 200, etc). In imperial, it tends to be in multiples of 25 (350, 375, 400, etc) rather than strictly 5. And that’s largely because, as you’ve noted, that’s the smallest meaningful resolution; the difference between 210 and 212 in either system is essentially random noise. Even a very good oven is going to fluctuate in temperature more than that.

Want to know something crazier, though? Before cheap and accurate thermometers, bakers obviously couldn’t use degrees in recipes. Instead they used “slow oven,” "moderate oven, and “fast oven” or “cool oven,” “medium oven,” and “hot oven”–clarified with “very” intensifiers as needed–to describe cooking temps for food.