We all agree that guilt always comes late and is undeniable. I can only say that if at that time you were not willing to hold your asset in the long term regardless of whether you needed the money or not then today you have nothing to regret. Take heed that long term holders are the real winners in this investment, but only for cryptocurrencies with potential like bitcoin and some of the best altcoin.
I'm just kidding, if the bitcoin price dump again to $5K (didn't hope that to happen) and most altcoin also experience it in 2022 or 2023, would you be willing to buy a lot and make a long term hold?
Anything can happen but I hope it won't be up to $5K. Of course there will be considerations to buying some Altcoins. My experience buying some altcoins after ATH in 2018 they couldn't grow, dev seemed to go and not take care of their coins. What survives today is one old coin, ETH. Others are even missing and delisting from the market. So how long you hold the coin you have to know when you're finishing. You should pay attention to the long-term prospects of the coin you choose.
But $5k is to much for a huge dump and provably will not happen knowing many whales will buy back at any figures if they see a huge dip already occur. Also those scammy things like dev abandoning their project is normal already on this space that's why its not good to hold the new coins since we don't know yet if they can last for more long time. That's why its good to hold the old coins since those are the one who tested by many bear markets already and yet they are survived for so many of it.