Personally, i think the term OP is a stretch. Heroes like punk are important for metas, but they aren’t very powerful outside of those lines. While most old heroes still can serve a purpose in battle, especially fortress. They do pale in comparison against newer toons. Howling claw, princess, hex witch are all awesome at first, but they dont level well against newer toons.
I think when a casual player, or spender gets to around orange 4 or 5, they need to retire heroes like elder and druid to focus resources elsewhere.
Theres a pretty simple identifier for which heroes are worth keeping. If druid, elder, ginger, claw, spellbinder, hex, squire, ect…were as awesome today as yesterday, they’d still be used in arena, RT and war defenses. Every time i see a howling claw or elder line in arena, i laugh because I know its a guaranteed win.