That's not too difficult to research which projects are still running in this bear market, there are actually many old projects but new projects are full of risks. Indeed, I agree that when the market is bullish, some altcoins can find other new ATH, especially well known Altcoin that can last a long time too. Long term hold are better but you are right, as an investor better find projects carefully, many altcoin will not pump when market recovers.
When market still bear very hard to research about which one coins have to buy and invest, I don't find top potential altcoin keep profitable when market still bearish. Maybe waiting if bitcoin have bullish and reach higher price very nice for researching about which one top altcoin to buy and hold, but if bitcoin can't reach higher price not any chance for getting profit although with few percent only because less consistent getting coins can reach higher price.