Prices of a coin that you see are the market given prices. It is based on supply and demand. Price can be fixed only if there is some less volatile asset to back the coin/token with. A stable currency can also be used (USDT, TUSD etc are the examples).
Yeah somehow stable coins is there because of the price stability and how it can hedge on the positions
But yeah, everything still goes back to supply and demand at last hmmmm
Price can't really stay if it is not pegged to something imo