Sometimes we don't see pump in the value of altcoins when Bitcoin surges but whenever there is a adrop in the value of Bitcoin it definitely causes chaos to altcoin market.
Well, there was nothing to prove anyways, most people involved in crypto already know that bitcoin is the one that drives the market.
The reason for altcoins not going up alongside of bitcoin is because most of the money is flowing into Bitcoin at that moment, if you follow BTC domination chart you can clearly see that.
Altcoins will have their moments though and they tend to increase in price while Bitcoin is relatively strong and is going sideways, but when Bitcoin is the center of the attention like right now you will only see the increase of the price on BTC and other high cap altcoins like Ethereum, other low cap altcoins can only increase based on good news and even then their pump would not usually last that much and they could just as easily get back to their original price after a while.