Thank you for your comment! Made me think.
Based on your example, it really feels like the passive investor does not make a direct impact. But you will agree, that an active investor surely makes a difference, right?
For example, instead of buying a cheap gas car, you postpone your consumption and invest in a company developing a modern electric car. After some years, the technology is there, and you can purchase a shiny new electric car with your returns.
So, when a passive investor makes a purchase, he will buy from an active investor (at least partially). Then the active investor can use this money to invest into businesses which have the biggest potential. So, indirectly, a passive investor also makes a difference.
True, but consumers aren’t the only customers. If the whole economy shifts from consumer mode into R&D mode, then all this R&D also needs resources. So, many “useless” businesses, which only produce non-essential consumer products, go bankrupt, but the ones that provide tools to further develop technology really start to flourish (like maybe schools & teachers).