From the past 4 years, if someone can buy and sell at the right time, they can at least earn 12x since the price on 2020 was $5K and now it's $70K. If they're DCA-ing Bitcoin from 2020, they're only earn 2x-3x.
Trader is better than investor, everyone can become investor, but not everyone can become trader.
It's not that easy. Many people thought they were great traders, but they happened to trade on:
Mt. Gox
BTC-e
Quadriga
FTX
I could go on, but many people won't even know smaller exchanges that disappeared with people's money.
Then there are other issues.
Even good traders sometimes make mistakes and mistakes cost you a lot of money. You can make a few great trades over the years and then a bad one and all your profits are gone.
You can lose the account somehow, get hacked...
As a holder I don't pay any taxes, but if I were a trader I'd have to do it every year.
We all have our plans for bitcoin and my plan is to hold. I've seen many of my friends try trading and do well for a couple years and then get destroyed by a black swan event like Terra Luna or FTX.