Some of those people who have been into bitcoin investment for the past 10 years have made a good fortune. I consider myself new to Bitcoin because I just got interested in it in 2019 (4 years now) and I couldn't hold anything more or less than $10 worth of it, even in 2020. But in 2021, I got a little hold of it and made some profit when the price pumped in 2021. I believe I will definitely make a fortune too if anything bad doesn't happen to the crypto market in the next six years, because already Bitcoin is facing lots of attacks by people just trying to destroy this technology.
More and more people are joining the Bitcoin community because of the obvious reason for getting a good return. The profit or ROI depends on what strategy you are adopting. There are people who bought bitcoin at 1$ and sell on 10$, while there are investors that bought bitcoin at 4k in Dec 2018 and sell at much higher prices. The best and tested strategy for Bitcoin investment is DCA. But again what strategy suits other may or may not suit you.