At least, we can reduce the amount of loss even with selling in this period if we holding good cryptos like BTC and ETH. It less likely to get low and have a good potential to come higher after all bad things blow over.
Yes, if for the time being it's better not to sell first because the price of Bitcoin and Ethereum is in good condition and always has a good increase, and I think people who don't have the chance to buy BTC and ETH when the price is still cheap will feel a little sorry to currently.
Ethereum has actually shown great signs in recent times and the announcements made by Vitalik Buterin have actually pumped confidence into a lot of investors but that said those plans need to be executed properly for the price to maintain itself and see a even higher growth in future.
I like the idea of ETH 2.0 and all the announcements being made overall, just keeping an eye on the implementation and how the market responds to it.
Coming back to what you said, I don't think anyone feels sorry to miss out on a cheaper price usually unless it is a massive drop like it happened in March and people who dumped or missed buying during that time might have regretted but not buying now I don't think is much of a reason to regret because price is although moving up, is pretty slow and steady.