People often forget "copy-on-write". Coupling doesn't have to be permanent. If refactor to create a sahred component, and then you want to modify a shared component to help one client, you can fork it -- it's not worse than simply not having created the shared component in the first place.
0 is only relevant for linear utility/impact functions The effect of an isotope isn't necessarily linear in its magnitude from 0. The baseline should be something that matters, like maximum safe dose.
The average American has no particular reason to stick with a "savings account". They could buy equities and ETFs that are as simple as savings accounts.
To be charitable, the Fed runs the money supply, but they don't control who gets the money. It's the job of Congress to regulate corporations and unions and minimum-wage and all that jazz.
It's not even a relevant comparison. "Corporations" don't spend profits on luxuries for themselves. Their human owners do. Owners pay capital gains tax (which you can argue is too high or low or too easily avoided.)
Insurers are paid in premiums, not health outcomes. An insurance company is incentivized to help avoid costly claims, but if you are likely to make costly claims, and they can't drop you, they are incentivized toward healthcare choices that kill you before you need long-expensive term care.