Actually day trading it is such a big business that big companies have spent huge money to make trading bots which can execute trades in milliseconds.
Day trading is indeed much more beneficial than simply holding any asset. If we talk about a volatile asset like bitcoin then obviously the chances to increase ones capital are more in selling and buying it on daily basis than after months. I personally support and admire day trading but it is also the most difficult and toughest job. Novice traders should avoid this.