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.
It is difficult for all of them to die since many projects have great potential and are completely worth it not to get lost in a simple dip that happens every so often and you do not have to see it with something strange.
Once it is prepared, everything can be taken in a good way. I would take into account coins that have repeatedly had great returns after a dip since these types of coins are the ones that are worth going to everything.
$DIVI is my greatest example, I can not even hesitate to say that it is one of my best investments in an altcoin, it is so accessible and easy to use its entire system that it is followed you understand it and without realizing it it is already giving you profits.
https://diviproject.org