Pinterest can work but not as “crypto traffic” in the normal sense. If you post coin charts, airdrops, exchange ref stuff, nobody cares or account gets flagged. The angle is more like beginner money content... saving, side income, “what is staking”, “crypto terms explained”, then warm them on a blog/quiz/email capture.
Also pins are slow. You might think it’s dead for 2-3 weeks then one pin starts getting saves and clicks later. Not the same as Telegram/Reddit where you can push fast, but for cheap evergreen newbie traffic yeah, worth testing imo.