There’s tons of robo investors that do fine. Indexes do fine. Find tax advantages and save a lot more than you spend. It’s controversial but I also suggest buying a house and paying off a mortgage, then buy a more expensive house and pay it off again. A mortgage gives you leverage but paying the mortgage gives you guaranteed returns. You live in your house which has intrinsic value. And being relatively illiquid you won’t be tempted to pull it in a risky direction or spend it. Do it 20 years and you’ll be in a beautiful home that’s fully paid off. If you do it right you can keep the houses along the way and rent them out to build a steady cashflow for eventual retirement.
These are the things I did. But by far investing myself into my career earned me the most, most reliably.