Just do it how most people do it, the easy and straightforward way. Earn fiat through a job, a business, or a gig, then use a percentage of the earned fiat to buy bitcoin in a peer-to-peer exchange. Or better, you can try to ask your employer to pay you straight in bitcoin.
This is exactly what I
didn't strive for. In order for people to spend their hard-earned fiat for crypto, they have to be very convinced that what they're buying is worth an investment. If they get some crypto for stuff they do anyway that's a much better way of introducing crypto / Bitcoin to average people.
Ok, on the top of your head, name one investment where you got 800% profit in one year? Also, Bitcoin is a high risk investment and should only
form a small part of your larger portfolio. There is no guaranteed profits in Bitcoin investments, but there are a huge potential for large profits.
Look at the price history of Bitcoin and you will several opportunities where people could buy low and sell for a massive profit. I buy/sell old cars
and I use the proceeds to buy more bitcoins.