Foreign exchange reserves are mainly US dollars, the proportion of which is unknown, and it is generally estimated to be as high as 70-80% or even more. With the depreciation of the dollar, the purchasing power of foreign exchange is indeed shrinking.
The main reason for the depreciation of the dollar is that the United States pursues a weak dollar policy, and China is the victim.
Moderate foreign exchange reserves, like a reservoir, play an important role in maintaining the value of the local currency and protecting the domestic economy.
However, long-term and excessive foreign exchange reserves are also very harmful. China, in particular, is hidden under the current account and capital account, and there are actually a lot of speculative "hot money", which will have a great impact on the economy.
When the United States pursues a strong dollar, it can buy resources and assets of developing countries at a low price with dollars. When it pursues a weak dollar, it forces the foreign exchange of developing countries to depreciate, and with the coming and going of hot money, it can use its own capital advantage to exploit the wealth of developing countries. So don't draw the wrong conclusion that the dollar is weak and the United States is declining. If a country's economy wants to be truly invincible, it must rely on "independent innovation ability", otherwise no amount of foreign exchange reserves will evaporate instantly.