Facing a positional 3-bet 500bb deep, the opener's plan is patience: flop equity or fold, never inflate.
4-betting narrows to the very top; suited hands with nut potential call more. The question on every street becomes: which hands are happy getting 500bb in?
Your hijack steal ran into the cutoff's 3-bet — position against you, and a range that knows your open was wide.
Assumes a standard 3-bet; 4-bet to ~2.2–2.5x the 3-bet. Deep, favor calls over 4-bets — a 4-bet pot at 500bb+ commits you with range disadvantage.