Yes true, as long the exchange is used and growing (more projects traded), it would increase the value of $Cake itself. Moreover if many projects came, they would buy cake to create /CAKE pair and lock it on liquidity, make the supply of $CAKE decreased on the market.
That's a very logical and obvious reason, as it will also be pretty much the same as BNB as there are more and more users of the Binance exchange which will certainly make them like BNB coin in general, so it's clear that Cake will get better if the Exchange is still operating very well in the crypto space.