My personal take:
Day trading is good when the market is both volatile and low. Post 2008 crash, I was working for a company that was making good money during the time (oil related) and I just couldn’t believe the market was correct for where it was so I jumped in to day trading via a company that didn’t charge for transactions. I regularly bought and sold on the volatility and did very well. There was only one stock I bought that refused to come up to a point to make money. ONE. I probably bought and sold a hundred. As the market rose, I started to stand pat on what I had and started to play the long term gains. Around 2017, I thought the markets were too high to have that kind of cash in it and started to sell off gradually. I’m now not invested outside of 401K.
Today’s market is not anywhere near as volatile as 2008-2009 and is definitely higher. I’ll sit this one out for now.