Two friends each had $100k in their stock accounts. One of them, John, bought TSLA at $220, now at $355. He sits on paper gain of 61%. If the stock goes to $2200 in a few years, he will have one million dollars, and owe a small percentage of tax if he decides to sell.
John's friend Robert decided to trade instead of invest. He wants to stay ahead of the game, but trading is a zero sum game. So Robert spent a lot of time searching/reading/posting on the internet. He did well that now he has $120k in his account. After short term tax is paid, he is basically back to square one, while the stock has gone up 61%. Robert decides to continue the trading game with full energy. What he doesn't know is some market participants have a lot of resources, they also use media to influence the market. In the end, by the time TSLA reaches $2200, Robert probably will have $150k in his account, maybe $130k after the final year's tax is paid.
If you have been in the market for a long time, you should know if you are really good at trading. Even if you did ok on paper, after short term tax, you probably are not doing nearly as good as long term holders. Think about those who bought @$20 and still sitting on the stock.
Those who buy at every bottom with high leverage can gain many folds in a year. That's not trading every little ups and downs.
It's all about knowing what's right what's wrong, and don't do the wrong things.