Easy is DC 10, friend. Which is why I say it’s not named based on “average Joe,” even if it’s calibrated based on his chances of success.we are using 5e table, ofc.
I meant to say, difficulty category spread by 5 works for 3e but does not for 5e, as skill bonus growth is much slower.
In 3e you gain +5(so you have equal chance to succeed on a category higher DC) every 5 levels, and in 5e every 20 levels.(or 10 for expertise).
also they boosted "easy" from DC 0 to DC 5. If "average Joe" fails a task 1 in 5 times then it is not really easy.