A lot depends on how long you will remain in your position and whether you want to have a retirement fund that you can take with you when you change jobs. Many academics end up with one employer for their entire career. We get the security of tenure in exchange for salaries that are low compared to what we could earn in industry. Once a faculty member has tenure they aren’t likely to move to another institution. Defined benefit pensions payoff wonderfully for long term employees. Thus defined benefit pension plans are attractive to faculty. However, if you are in a tenure track position and you don’t get tenure, your preference for staying with that employer won’t matter and the pension plan will be almost worthless to you.
At my institution, new assistant professors mostly choose the defined contribution plan over the traditional pension, largely because they don’t know whether they’ll be long term employees or not. That’s how I decided on the defined contribution plan when I started as an assistant professor. Fast forward 10 years and I was a tenured full professor with a secure position wishing I’d opted for the defined benefit pension plan.
A decade ago, my state offered us tenured faculty a one time chance to switch to the defined benefit plan from the defined contribution plan. After discussing this with my financial planner, and considering that I will most likely finish my career with this institution, I opted to switch to the defined benefit plan. I’ll end up with a fairly good pension after 25 years of service (from the day that I switched- no credit for time in the DC plan), plus the accumulated investments in my defined contribution account, which has come back reasonably well from the Great Recession.
Under the new rules, faculty all get a one time chance to make this switch when they are awarded tenure at seven years of service. It is a very nice option to have.
Of course, none of this says anything about the risk that your pension plan will default. In the US, there have been many situations where private companies underfunded their pension plans and subsequently went out of business, leaving their pensioners without promised benefits. There is the Pension Benefit Guaranty Corporation (PBGC) that backs up failed pension plans, but if the PBGC takes over your pension you can expect substantially reduced benefits.
There is somewhat less of a risk of this happening with a pension plan funded by a state or local government simply because that government is likely to continue to exist and generate tax revenue for a very long time. Defaulting on pension obligations would be a significant crisis for any government, so steps are typically taken to prevent collapse before it occurs. Since pension contributions and liabilities unfold over decades, there is plenty of time to address any issues. Over the decades, a small increase in the employer or employee contribution rate or a small decrease in benefits can make a pension plan sound again.
In comparison, if you have a defined contribution plan, then the funds contributed by yourself and your employer are in an account that is under your control. Those funds can't be taken away from you, but you have to invest them, and the return on those investments could vary dramatically depending on factors that are really outside of your control. If your investments do poorly (consider the Great Recession of the late 2000's) in the years just before you retire, you could end up in a very difficult situation. If your investments do well, then you could become quite wealthy and be able to retire early.