You only have two options either to Sell it or just HOLD.
If I'm in your place, I SELL them and use the money to invest in Bitcoin. Holding them is somewhat riskier, maybe if we can manage to wait long but for us who are short-term holders, the best option is to divert our portfolio. of course, we lose some of our money but we can still recover it if we reinvest to the other project.
If it was another coin and that was a risky one, I would agree with you. Link may not be the best coin out there, but it is one that is usually along with whatever the market is doing as well. Which means that the drop was mainly because of the drop in the market as well.
If he bought ada, that would have dropped too, if he bought bnb, that would have dropped too, whatever he bought at the time would have dropped. Which is why holding is a better method, even buying some more to drop the average could be even better right now. This is of course true for just Link and few other coins, not for general approach.