Not enough people have these amounts at retirement. But something I find interesting, is far more have 750k-2M than you think do at retirement age and still struggle. And the rule of thumb has been 10x saved in retirement accounts based on your last few years average income, will let you maintain a similar standard of living during retirement (but rarely works that way in real life). Many medical expenses are not fully covered (ask an older person about this), even people who have 10x are not "safe" as just one medical problem could wipe out most of their savings/income. And talk to a financial planner and an attorney, as depending on how you setup your savings it may or may not have any protection at all, most of the time it doesn't when you are living on it.
Why do you think everyone moves to Arizona or Florida etc from NY, NJ and CA etc after they retire. Most move because they have to try and lower their cost of living because what they saved isn't enough even after retiring at 65 or 70. I live in Florida and see it all the time with the influx of people coming in.
My point to the OP was if you want to "retire" which to me means never work a day again, than you need to have a lot more stashed away to deal with the unexpected than you realize. If you are 25 $10M to retire will make retirement pretty easy, $5M will mean you need to keep your cost of living low and watch your spending, but you can do it. Add 2 kids, college and maybe one divorce in there though and you are quickly staring down a nest egg more like $1-2M. Then add in a fairly minor (cost wise today with insurance) medical emergency like a heart attack and even with insurance you could still be paying $10k and upwards of $100k easily. Now factor in after that heart attack your life insurance rates and number of medical visits and medication bills is going to skyrocket, so you may easily start spending an extra $15k/year. Just a point on the medicine part too that I have seen multiple times, my mom had a medicine she needed and the cost is roughly $1200/month, but if you can show hardship then you can get a major break from the manufacturer (like free to $30/month for 24 months). Guess what you can't do if you have assets, you'll never get the hardship discount so you will be stuck paying full costs, or nearly the full cost as you can usually find some discounts (so add another $14k just for one medication).
Hopefully that explains why financial planners will give you different numbers depending on what you tell them your goals are, which is also why I highly recommend people find a real financial planner and not wing it from the internet.
BTW: I am familiar with the FIRE movement and while I agree with parts of the thought process (especially saving and living below your means), it isn't going to work for the majority of people. And while it would protect you from one moderate car accident and/or medical problem which usually coincide, you'd could easily be nearly broke afterwards. Then what do you do, try and come back into the work force 10 years into your "retirement" with out of date skills and fighting age discrimination (it still exists everywhere). Not saying don't do it, just don't be naive about it.