People do this because they want to enjoy the benefits of early pump and after the coin pumping has exhausted, they pull out their investments because they know that when a coin is having a potential, people will rush to buy just to get quick profit but this is importantly work when the market is very excited like in tbe bull run, trying this in bear market is nothing but a disaster that will come later because they don't get pump that much.
BTC is the best, if there is any coin that is close to perfection in design and coinomics is btc but bitcoin can not give exactly such type of profits, like the coming halving that many people are expecting, the highest I think we can do this time around will not exceed $100k if we really want to he honest about it but there are acoins that can do 20x easily with proper research.
This is the best solution and strategy anyone who have investment plans should do, never depend on a single coin to give that result you want to have, they will disappoint at the end and that's why it's good to always diversify your portfolio so that when one don't pump, the other might pump and will give you good profits.