It will depend on politics and tax laws as much as anything. Pensions were created because the tax code favored them. When tax laws changed, the focus on pensions shifted to IRAs and 401(k)s.
More recently, the big shift has been from "employee" to "independent contractor." Again, the companies do this because it makes the most business sense -- they don't have to offer benefits, nor do they have to pay the employer's share of SS or unemployment insurance (not sure about workers' comp). DOL has historically been the force that drew the line and forced companies to treat people as "employees," but that has been waning for a long time due to the priorities of the more recent political appointees. And the decline of unions mean there is no countervailing force to compel employers to treat people as employees.
The Covid era, I think, will further push this along, as it illustrated how feasible it is for many people to work outside of a formal office environment and collaborate virtually. Employer control over time/place/manner of work has been one of the major considerations in determining whether someone is a contractor or employee, so making work location/hours flexible would enable more companies to shift more people over to the contractor side.
We will always have a significant portion of the populace that is considered an employee; even if the local restaurant is owned by an individual, they still need to hire people to work there, and it would take a major change in law for those kinds of employees to be considered independent contractors. But even there, we are seeing the growth of companies that are themselves contractors who provide their own employees to do jobs -- e.g., janitorial services. Ultimately, the individuals are employees, but they are employed by the contracting company, which of course takes a cut of the profits, so it's likely worse for those individuals than if they were hired directly by the office.
My worry is really the hollowing-out of the mid-tier jobs. People with skills in high demand can do well either as employees or contractors; conversely, there will always be low-paid service jobs for the people with minimal skills. But the whole teacher/firefighter/nurse kind of work that created middle-class lifestyles is getting broken up and parceled out. For example, in nursing, we have massive credential inflation -- we've gone from 2-yr nursing degrees, to 4-yr degrees, to post-grad degrees being expected to get the best pay. We have also divided out types of nursing to allow NPs to do some of the stuff doctors used to do (with, again, additional credentialing). You literally cannot get a job as a physical therapist now without a Ph.D! The folks with those various credentials can do well. At the low end, we have a tremendous number of minimum-wage jobs as "aides" or "assistants" who work in hospitals and offices and people's homes for very little money. And often you need some number of hours in those positions even to be admitted to a program to get the better credentials. So again, the folks with skills and ability and enough money/time to study and volunteer and all can do very well, while the folks who can't will struggle on very low wages. That great middle-ground seems to be getting narrower, and the path to get there steeper.
I'm also thinking about firefighting, because one of my son's HS friends has been focused on that since he was about 16. I had NO idea the number of classes and certifications it took to be a firefighter! And even then, there are more classes and even a year-long fire academy to move up and get paid more. He spent 2 yrs in HS doing this stuff, and this past year out of HS taking more classes, with the hope to be admitted to the fire academy in the end. Right now, he volunteers at the local station, because he needs a certain number of volunteer hours for his next certification; he works as a plumber on the side to earn money when he's not studying or volunteering. And if he succeeds with all of this, he'll get a job paying around $65K -- not bad at all, but damn that's a shit-ton of work to get there. He'd make better money as a full-time plumber.
