If a person trades considering all the aspects of the trading platform and all the strategies then he can make profit in both the seasons. For example, if you can analyze the market when you do futures trading, then if the market goes down, you can definitely profit with a Sell/Short order, because when you take a Sell/short order, the more the market goes down, the more profit you make. On the other hand, if you trade with aBuy/Long order, the higher the market, the higher your profit. So in this case I mean if a person can analyze the market then he can be successful in trading in both seasons.
How good a trader is, he can find out himself from his performance in a bear market, because in a bull market, many can boast of good results. Strategies can be anything, the most important thing is that they bring results, and if a trader gradually loses his trading deposit in a bear market and only starts to replenish it in a bull market, then you understand how good such a trader is.
Of course, in the end, we will be able to evaluate the results of the trader, according to his final trading balance, whether he is in profit and for what period.