Fundamentally, investments are a bet that the future will be richer than the present.
If there aren't enough good investments now then that's an indication that the market believes there are major structural problems with the economy that will prevent the future from being richer than the present.
That's a far, far, more serious issue than just a question of what the kind of people who expect to receive passive incomes will do with their time.
Obviously, the pandemic is having a major current impact, but as you say, there has been a shortage of good investments since at least 2008.
I believe the underlying issue is a misallocation of resources into rentier economics and not enough into productive growth. We've collectively put far too much money into monopolies that squeeze larger percentages of money out of people and not enough money into innovation that improves the human environment. We need more of the original Google (i.e. the revolutionary search engine) and a lot less of the current Alphabet (i.e. the rentier advertising monopolist).