It's not the full story, but it's certainly a large part of it.

I'll chime in tangentially with another large part: the disproportionate share of both asset and liquid wealth held by people who are some combination of a) Baby Boomers, b) in the top percentiles of wealth/income, c) politically- or socially-connected. As you say, it's not all of them, but enough of them. At the confluence of the two groups is a desire not to invest in potentially risky ventures, or to spend on consumption, but instead to put as much money as possible into a narrow band of low-risk, often passive investments, and to pull every lever possible to protect those investments, even when they become outmoded in some regard and the income stream or economic activity that supports their high (growing) valuation dries up.

Supporting this paradigm (ostensibly so that seniors don't die in poverty, so that strategically-important businesses and ventures are backstopped, etc., but, crucially, to the detriment of all other concerns) means an erosion of a sort of "constructive inefficiency": "wasted" spending on ventures that might not work out, on employees who are not the best and most productive, on niche services and products, which altogether represent a massive share of potential economic activity that is much better at involving and supporting a diverse population with diverse needs and diverse skill sets that perhaps have not yet found the correct outlet to produce maximal value.

Your C-suite goons and my rich, highly networked seniors don't care about the potential of a paradigm shift to support and enable short-term losers, though. They just want to pile into the sure-thing of your "actually good businesses" (which, in many cases, aren't actually that good).