Indeed, what you say is true, but on the other hand, maybe you have to look at the coin first, because it is true that when there is a market fall, there will definitely be an increase there. But on the other hand, we also have to understand that not everything will return to normal, especially maybe for some altcoins which are basically shitcoins and projects that are not clear.
The situation only applies to bitcoin and some of the big alts like BNB or ETH but for everything else maybe I think it's not as smooth as one might hope.
Many new Altcoins are created with the aim of scamming or something like that which makes buyers lose their money. If you really want to contribute to a new project, you must be aware of the risk that your money can be lost when the project becomes a scam, while making purchases in Bitcoin. BNB or Ethereum which has clear developments will be safer even though the profits will take a very long time because the price movement process of this large coin depends on market demand.