For someone trading conservatively, focusing on a few trading pairs is much better, especially high with high marketcap coins couples with higher time frames is the bomb. The only disadvantage is maybe lower PnL over a long period of time but the risk of losing a trade is way so low.
People opt for so many trading pairs because they feel they might at one time land on a gem that can easily go x10 in a few days. Of course this happens at times but not always. To answer the question, I think it just depends on one's strategy
The frequency of that not happening is so high that there is no reason for people to think that it would be a good idea. They think that they can make x10, but the amount of people who lost more money trying to make x10 is a lot more than people who actually made 10x, which is why I think it should not be all that easy to keep that going.
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Can't blame OP, every trader has some specialty or technique, for example, some based on trading volume, some on the moving average of prices, and some based on the candlesticks' patterns or momentum.
I am agree with OP also trying other trading pairs so he/she will know how trading really works, like trading other pairs with low trading volume versus high trading volume.