Ideally you should keep them, for now if selling is an unwise option. We can pray by 2022-2023 maybe these cryptocurrencies can grow back to the value it once peaked. The global economic market has not yet collapsed so we should not pray that crypto can grow steadily.
I agree with you in 2022-2023 that's why hold is the best solution, if someone will add assets to the future at this time is good to buy not sell 