First of all, these wells are all Lock Longjing, with underground ditches or streams below them, and even some wells are the same as underground rivers. Therefore, after the jewels are thrown into the well, except the heavier gold and silver jewels, other lighter jewels will follow Shui Piao. So, after those jewels were thrown down, they were washed away and nothing could be found.
In addition, the wellhead of the Forbidden City is relatively small, and people with slightly fuller bodies will get stuck in the wellhead and cannot move. If you must salvage, you must use special equipment, but it is impossible to use professional equipment in such a narrow place, and some places are blocked by rocks below and need blasting tools to dismantle them. This will destroy cultural relics and cause riots. Therefore, the salvage work cannot be carried out smoothly.
Later, after the demise of the Qing Dynasty, warlords also allowed Puyi to continue living in the Forbidden City. Because there is no economic source, the eunuch in the palace also salvaged some jewels from the well to sell. After Cixi fled back to Beijing, she also searched for treasures everywhere, and there were even fewer treasures in deep wells.
To sum up, no one goes to salvage it not because they don't love jewelry, but because there is no jewelry to salvage.