1) The difference between degrees is massive. Statistically (so I am ignoring cases) a history, literacy, or arts degree is often worth much less than most STEM degrees. At some point I read that people in business withOUT a business degree tended to earn more than people in business with a business degree, although I never looked much into it past getting a chuckle.
2) One of the main reasons for pursuing FI (lean or not) is to get additional options, more choices, or as some phrase it more freedom. Having a college degree opens a lot of doors ranging from easier networking/interviewing, MUCH easier time changing career paths (I did this and having a degree helped me massively), all the way down to having been forced to have a more in-depth education letting you know things your peers may never have been informed about so a wider range of potential interests.
3) Related to number 2, you can pursue leanFI and leave out the RE if you find a career you enjoy. Sure, maybe you can be FI a year or 2 sooner without a STEM degree from public college, but if you are more likely to access a career you enjoy those extra 2 years are well worth the decade+ of working career both paths have.
4) Again related to above, some people have very narrow interests which are nearly impossible to get jobs in without that piece of paper. Someone who wants to work as an architect, archeologist, accountant, etc is going to have an extremely difficult time doing anything in their field of choice without a degree. Not everyone wants to be a plumber, programmer, or administrative assistant.
5) Plenty of edge cases exist where a college degree end up being net-positive. I had a degree then changed careers to become a software developer via a programming bootcamp. My degree opened up certain doors which my peers in the bootcamp did not have (many only had high school diplomas or GED) and those initial doors led to me having even better openings available since I still had the degree, but more importantly I had much better work experience since I initially had better offers out of the bootcamp. It is VERY hard to be able to track accumulated advantages which a degree can offer.
I totally agree that frequently college degrees end up being a net-negative for people. I also think that there are many (majority?) of cases where non-degree paths work out much better. However, there are plenty of FI-related reasons to get a college degree.