Trading 2 pairs would be better for me rather than focusing on many trading pairs. Trading with 2 pairs as long as you're making money on it would always be better than trading with so many pairs but making way lesser than that of the first one.

Add also the fact that it will be more stressful for some traders to monitor charts of many coins. I also tried trading that's why I know that monitoring many charts of different coins is stressful than just focusing on 1 to 2 trading pairs. In general, I still believe that there are some expert traders out there who don't want to focus more on 2 trading pairs, but they want to focus on more trading pairs because they believe that they can get more profit when they trade that way. Well, as long as they aren't stressed with it, and they are making way more profit then it's good.

Experience matters on this one. If you're a trader for many years already then you can opt to trade with multiple pairs and still make profit.