The phrase buy the dip is only a good advice when you apply it properly by buying the very good altcoins whose value is only down because of the bearish market condition. Because it is not all coins that dip that would recover their value.
For example, early this year (when the market was super bullish) almost all the projects released saw good increase in their value. but that doesn't mean it is all of them that were very good projects. After the market dip (correction), most of them never recovered their value. The crypto market is filled with a lot of scrap altcoins and the market way of sheding them off is to dip (correction). So it would be in your best interest to only buy very good coins in the market dip.
These are coins circulating in the market today, sometimes up and down and down, moreover we can't apply it well in buying some coins that we think are good, but in fact these coins don't give a good increase at certain times.
Corrections that often occur in coins, when there is a burn that is carried out but does not go well and cannot restore its value, thus forcing the coin to fall to a very small number and cannot bounce back at a certain time.