Sure they do. There are plenty of smart, prudent retirement plans for companies to offer to their employees that don't involve crippling liabilities down the road. Defined contribution pensions, tax free retirement accounts, dollar-for-dollar matching (up to a limit) etc.
Defined benefit pensions were a bad idea born of a "I'll be retired before then so let's kick the can down the road" mentality.
My current employer defaults employees to 10% and does dollar-for-dollar matching, but there's people who opt out because they want (possibly even need) all of their salary now, and thus they don't get any contributions in their plan. Yet these are precisely the people who would most need the contributions, because they're least likely to save up money in other vehicles!
More to the point is that defined benefits, in addition to their other issues, are mostly oriented to long-term employment with a single company. If you move around every 2 or 3 years, you probably wouldn't get much if anything out of traditional defined benefit plans.
Traditional defined benefit pensions are nice in some ways for workers in that they're predictable. I'll even get a small one myself. But, like employer provided healthcare insurance, they're really not a good match for most purposes today.
A well-executed, professionally administered, and properly run defined benefit pension system is by far superior to every other option on offer. It offers predictable costs for the employer, predictable benefits for the employer, and all of this will continue without the company for as long as the pensioner lives.
In practice, there's been a lot of subtlety to this. It's very easy to make changes with low-visibility long-term negative impacts and high-visibility short-term positive impacts. Public-sector pensions in the US have famously assumed unrealistically high discount rates, among other things, because that turns into small contributions in the short term which employees and unions love.
Decades down the line, everyone gets screwed. But the people who made the bad decisions are well beyond accountability at that point. Since they know this, everyone involved is incentivized to think short-term. Never mind the issues that arise when life expectencies increase well beyond what pension fund planners knew to work with.
The popular workaround for this is a 401k or similar. This isn't ideal by any means. It takes away the defined benefits and the predictability and certainty for pensioners! The main upside is that it also removes the kind of misaligned incentives that can encourage poor decision-making and provides more assurance that something will be there later in life.
You're completely right. Pensions, when done properly, are amazing for everyone! The alternatives kinda suck by comparison. But they're much better than the answer many pension funds have provided.
(Salaries, being compensation for a defined term as well as defined amount, can be terminated, and are also compared to current value provided. And aren't assumed to generally last until employee death.)
Let's debate what works without pretending everyone who disagrees with us has terrible motives. Defined benefit plans provided huge benefits to many workers who have not managed the switch to defined contribution plans well.[1] That does not mean that pensions are sustainable, or even that they are a good idea, but their proponents are not just con-men.
[0] https://www.thebalance.com/the-history-of-the-pension-plan-2...
[1] https://www.cnbc.com/2015/03/20/l-it-the-401k-is-a-failure.h...