> But if you're a normal worker, just save a lot early on, keep saving at a decent pace, and cash out early if you can.
Not everyone can. Two groups of 'best laid plains' derailing people quickly come to mind:
Many of my co-workers, and myself included, got divorced in their 40s and set back financially 10 to 20 years. It doesn't matter than in the vast majority of cases I personally witnessed their spouses were unfaithful, wanted to try for someone new, or were just tired of being a parent and wanted 'to be free' - as the main breadwinner for their families they usually wound up on the short end of custody and the big end of paying out support for years.
Additionally, financial black-swan events, like losing one's job during the 2008 crisis followed by extended unemployment, caused many people to have to 'cash out' their retirement savings in order to survive financially and not lose their homes, etc. Not only did they have to sell their retirement account assets at fire-sale prices, they got to pay the extra tax penalty for doing so. Many who fell into this camp were also set back decades financially.
My point is, even when individuals "do everything right" financially - working hard for years and years, diligently saving for retirement while trying to live life, raise a family, and generally trying to do a little more than just exist for their employers - their financial world can be upended and they find themselves looking at retirement before 70 not even being a possibility. And what 'safety net' do we have for them? none.