While we might all become richer collectively, we will never feel more successful unless we have someone to compare ourselves to.
A few examples come to mind. One is the craft beer scene. Microbreweries often adopt a collaborative business model with other breweries in their area, rather than being cutthroat and trying to run each other out of town. When a town becomes known for having a thriving beer scene, it attracts more customers in total, to the benefit of all the breweries there. It widens the proverbial pie. Thus, by association with that scene, all the individual businesses become more successful than they would have been otherwise. And in that case I'd say success is about more than money - name and quality recognition, and building a dedicated fan base would probably factor into it as well.
Of course there are limits to that model, such as a local market becoming too saturated, but I think it's a good example of success being a more nebulous term than only being dependent on defeating others.
Couldn't that someone be one's ancestors, or even one's past self?
It's time we stop pushing this STUPID narrative that software can make you rich if you are just willing to throw your user's interests out the window and "work harder". That is not how this works.
On top of that developed economies tend to grow slower - we may all be millionaires by early 70s standards with our fast cars and air travel, but I don't think in 50 years we will be millionaires by today's standards - there simply won't be that much growth in the future.
Investment supposes this is not true because wealth is not an evaluation of liquidity. The hardest thing to realize is that that's poor people thinking and you're already behind if that's how you operate (ie the vast majority of the world, including me).
To illustrate my point: can you imagine everyone living off passive income today?
See Paul Graham's essay on wealth, specifically the subject about the pie fallacy. "...although there may be, in certain specific moments (like your family, this month) a fixed amount of money available to trade with other people for things you want, there is not a fixed amount of wealth in the world. You can make more wealth. Wealth has been getting created and destroyed (but on balance, created) for all of human history." [1]
[1]: http://paulgraham.com/wealth.html