If you haven't done your profit plan it's better done now or dwell in regret when the bear moment starts.
This statement is true for shitcoins provided you make profit from such coin already, but losses are more likely, but profit can be by chance, then such person should sell the shitcoins and buy bitcoin because the statement is not true for bitcoin, nothing like regret, you will gain. If the price fall, do not sell but just hold and the price will increase back and reach ATH, then no regret. But some people may want to sell for some good reasons, maybe this can apply to them, but there is nothing bad to always hold bitcoin.
I don't see any point in buying coins in a bear market when the price is going down every day. This applies to all coins and even Bitcoin. In this case, it is better to keep stablecoins, and then, when the market turns around, buy coins that you are interested in.