Sorry if it came off that way, I am certainly not one of the "fearful" kinds who discount it's value to 0. Simply so that, during FIRE, your biggest risks are early on. The first 10 years determine the majority of your chances at success.
In that same line of thinking, people might avoid thinking about SS in these calculations because they are focused on the sequence of returns risk and SS falls outside of this. (Arguably, this risk is the largest such risk in FIRE). If I am FIREing in my 30s, SS is so far outside of this range it's hard to see much true value in it.
By the time I reach 65 after being FIREed for 30+ years, I WILL be so wealthy it won't change the picture. The only situation it seems to matter at all, is one where you don't go broke PRE SS age, and you ALSO don't become wealthy or even maintain your wealth. A situation where you are in declining stache and SS catches you before the bottom. In this situation, many would either pull back spending, find some side work, or some other method to avoid it anyway.
Ah, I see where you're coming from, thanks for that. Yes, I understand and agree with you about how if you're
retiring in your 30s, sequence of returns risk pretty much obviates any thoughts about Social Security down the road. But that's a bit different than saying Social Security doesn't or shouldn't matter at all to people
in their 30s, who may not be retiring just yet, or that Social Security will be "eaten up" for those people.
Those who are looking at a less-than-30-year window between retirement and drawing on Social Security probably want to consider how the expected payout affects their overall wealth/income later in life. For example, to use an extreme case just for illustration, if someone determined:
1. They could live off $20k annually, and
2. Their expected SS income at 62 (adjusted for inflation) will be $20k,
then they could save just enough so that they draw their stash down to $0 on the day they reach age 62, at a rate of $20k per year, during those intervening years. That would cut many years off the time they need to work/save vs. having enough, say, to draw 4% "forever."
Obviously this example would be a ridiculous, high-risk endeavor fraught with peril since no one can plan a drawdown that exact, but I want to make the point that drawing down the stash and using other income streams later in life, rather than having the stash go on infinitely, is a viable strategy. It doesn't have to be black-and-white -- having enough stash so that SS doesn't matter at all, or being in peril and cutting back and getting side jobs just to barely make it to the time you can draw on it. It can be part of a well-thought-out plan for drawing from different "buckets" over time.