I have some that have self-sown in fairly shady areas, only dappled sunlight, and they seem to do OK. It is by its nature a very short-lived plant, I consider it more of a biennial really, often if they come back for a second year of bloom that growth is very weak, and a 3rd year is pretty much forget-about-it. Luckily, they seem to self-sow well.

I have plain Echinops ritro growing directly under a greengage plum tree, right up to the trunk, so probably you'd call it dappled shade. It is a reliable hardy perennial here. Mine is pretty old, at least 7 years I should say and probably more. Must be to do with the climate. It increases slowly in width but has not self sown. Surprisingly the centre has not deteriorated and remains vigorous. Much enjoyed by bees.

Basically, Echinops are long-lived, but:
1)they drown easily in winter
2)they are susceptible to some kind of fungus at the base of the stems or even in the crown itself, causing wilting even in the middle of the summer. I have learned that I can save such a plant by digging the crown up, and the plant will usually return from the roots.