For me, all this sound sketchy and very far from the original intent of creating a coin that offers certainty and trustless exchanges.
I do not think that manipulating the price of Bitcoin will be easy, but rather volatile, because there are about 90% of the supply in unknown hands and it can be added to the market to control any insane rise in prices or vice versa. Therefore, for large whales and platforms, price manipulation in the medium and short term is very possible.
There are also more than a million bitcoins that we may not know who owns them.
Tether (USDT) is a compromise solution for traders and even if it is not present, the platforms will find a way to fix the price.