>Depends on when you started investing. Compounding interest is only a powerful force in your favour when (implied) interest rates are above zero.
There's no point in my life at which I could have started investing wherein I would be underwater now. No point in my parent's lives, either. if you take a 'buy and hold' approach with broad low-cost indices, you are going to have a hard time finding a date where if you bought and then sold ten years later you wouldn't have beaten inflation by a reasonable margin.
>And still: every working hour of older people is on average more expensive to give up on some startup.
This bites both ways. I can point out several mistakes I made running a business in my 20s, mistakes largely due to inexperience that had I not made those mistakes, my business would have been opportunity cost profitable and then some. Yes, I get paid more now than when I was 25, but I also produce a lot more value, and a lot of that extra value, the "wisdom" as the old people like to call it, is outside of my abilities as a unix tech or a programmer (though I'm better at those things, too.) I am worlds better socially, and have a dramatically deeper understanding of business.
(you can argue that the business skills are because I spent my 20s running a business... and you wouldn't be wrong, but I would have learned some of that working for other people, and my social skills? those are just me getting better at life, in fact I think my social skills would be better still had I kept an office job during that time, and having better social skills will help you dramatically in business.)
I personally think that my increased pay does not nearly capture my increased value. I am dramatically better than my first coding job... and I only make like 4x what I did then, and that's not counting two decades of inflation. Running a business is one way to capitalize on both your technical and your social skills.