Cushions:
Soft on the butt, zero help for your spine. Pain stays.
Lumbar pillows:
Wrong support, wrong height, pushes you forward, and you must sit all the way back. Most people end up buying multiple lumbar pillows that never fit right.
New “ergonomic” chairs:
Expensive. Comfortable for 20 minutes. Bad back-support design hurts you after hours. Designed for aesthetics, not human backs.