some people that wants to buy using the lump sum strategy sometimes also wait for a dip so they can buy.
I guess that you are misunderstanding buying with lump sum and buying at the dip. When you are buying with lump sum, it means that you are buying right away irrespective of bitcoin price at that moment. For instance, if you are paid bonus at work and you use the money to buy bitcoin immediately is called lump sum because you don't need to keep the money and be waiting for the dip before buying.
Buying at the dip is when you keep some funds and wait till bitcoin price dips before buying and that is not a good practice for a no coiner or low coiner to use without his DCA going on regularly.
Actually it somehow apply in that scenario but it really depends on the investor using this method since lots of people commit a mistake for waiting to much on the dip since common scenario happened for individuals who don't have a experience is they got afraid to see more dumps.
Waiting for dip is actually not a bad practice for people who use lumpsum method since actually they can take advantage on that scenario to get more cheaper bitcoins and put all their money intended for investment then wait for long time.
What I think wrong for waiting for dip is people who use DCA method since this will delay their accumulation and they might commit wrong decision if they always thought about wait for a dip is best for them to do. But for sure we can learn a lot more information here since everything is been discussed and its good if we could read different opinion and correction since it can enhance more our knowledge so let see if there's more bright explanation towards this things and lets learn from it.