My parents view pensions as gold standard. That it cannot be messed with and clearly this article shows that it can. The promise for your years of service can't be paid out.
Now something you believed would allow you to not worry until your passing, perhaps leave a small something to your children, won't be. Instead, you're beginning to worry about how you'll make ends meet in a few years with all the rising prices.
Defined benefit plans rely on the firm to correctly manage their pension plan, allocate funds for it, invest them wisely etc. In public sector there is political pressure to reduce forecast costs of a defined benefit pension. In many places it's completely legal to operate an underfunded defined benefit plan. Defined benefit plans are also traditionally fixed to a single employer, they don't fit well for a more mobile labor force.
For defined contribution plans individuals actually have control of the pension funds - they are just locked from access til retirement. They are generally government run, you aren't locked to a single employer. Individuals can set their own risk appetite and make their own decisions regarding fees etc.
Defined benefit plans are really popular because the pension amount is "guaranteed" but this guarantee is just an illusion. You can't magically make risk go away, just move it somewhere else. Many examples of defined benefit plans that blew up/were restructured/cancelled etc. Defined benefit is just a plain bad concept.
Defined contribution plans in the USA typically have an extremely small contribution by the employer. Works out great for the employer. Doesn’t work out so great for lower wage earners as they struggle to fund the plan.
Note that all three of those are subject to democratic capture, in which low-information voters enable the pension managers to make poor risk and actuarial decisions. Of course, a defined-contribution plan is also subject to low-information control, but at least the damage is confined to the one making the mistake, not to those unwillingly along for the ride.
I understand that defined-contribution plans must offer similar terms to both executives and regular employees, specifically to help ensure that they are fair to employees.
You mentioned low-income workers twice, but I don’t see any inherent advantage to defined-benefit plans or inherent disadvantage of defined-contribution plans for them. It is arguable that low-income workers are also less educated and less likely to make wise or even reasonable investment decisions when in charge of their own funds. Of course, they are also less likely to make wise decisions in the choice of their pension managers.
Another huge advantage of defined-contribution funds is that one owns them and can pass them on to one’s heirs, unlike defined-benefit plans.
There is an advantage to defined-benefit plans which also come with insurance (e.g. disability), but I suspect it would be more efficient to unbundle them.