Because the volatility of bitcoin moves the entire cryptocurrency market, if it falls, all those '100 more advanced cryptocurrencies' fall in value as well.
So it's pointless for me to use something like Cardano only for the price of it to fall because of Bitcoin rendering my holdings significantly less than what it was.
And don't get me started on Ethereum fees due to congestion and networks like Polygon going down all the time, doesn't seem advanced to me if congestion is still going on.