The reasons for Bitcoin's rise have been found

Dollar depreciation

Public and institutional distrust of the dollar has led to a massive outflow and sell-off of dollars

A portion of the assets has flowed into the gold market, as gold has safe-haven properties

A portion has flowed into Bitcoin, which occupies 58.92% of the total market value of the cryptocurrency market

This has led to the rise of Bitcoin while altcoins remain stagnant.