French “blues” are a bit of a lottery IME (for “beginners” or those who just want to cruise all day). Sometimes they’ll just flow gently, then chuck a steepish bit followed by a long flattish run out. Resorts want to show as many blues as possible on their piste maps as that’s what attracts most skiers.
I haven’t skied lots of different resorts, but from what I remember, Zell in Austria had a lot of easy blues – it’s where I fell in love with boarding (again, having tried it a few years previously in Montgenevre) – because I could cruise easy blues, putting in lots of big turns with plenty of room.
Of course, how easy a resort’s blues are will depend a lot on snow conditions. An icy blue will still be a tough one to board for anyone starting out, especially on a rental board with dodgy edges.