If we actually get universal health care in the US, I could likely retire by 50-55 (house will be paid off, kids' educations are paid for). If we don't, then I'll need to go to 60-65 to keep coverage for the kids (family history of early adult cancer, so I want them on good health coverage for preventative screening in their 20s)
What's to change? If you want to retire by 50, then you need to adjust your savings rate to match. It means you'll probably want to go to a cheaper school to avoid massive student loans. You'll probably want to rent it if you buy a house it'll likely need to be cheaper than you would otherwise buy in order to maintain your savings rate. You'll need to investigate your savings vehicles and plan for things like Roth conversion ladders.
The "official" retirement age only matters to Social Security. 401k and IRA withdrawal ages can be worked around. Everything else is up to how focused you want to be on FI/RE vs taking vacations, buying fancy phones, etc.
Healthcare is unaffordable. You'd never realize this working at Microsoft. Buying half decent private insurance for a 50 year old couple with a couple of kids will cost you closer to $2500-$3000 per month in today's money. God knows what it will cost a few decades from now.
Yeah, health care is my main blocker as I mentioned above. But I wouldn't want to tie that only to retirement to avoid solutions like "reduce the Medicare age from 65 to 55". We need Medicare for All, not Medicare for Early Retirees.
The rest of my point still stands, that the "rules" around retirement do not percent people from retiring early, though they may incentivize people to retire late.