You’ll be exposed to tens of thousands in risk per year on top of (low) tens of thousands in premiums per year for a family Exchange plan. You’ll be burning nearly half of that (and spending all your free time trying to keep hospitals and insurers taking even more) if one of you gets cancer—or, if it’s you who gets cancer, you better hope someone else can handle that.
You also can’t withdraw at as high a “safe rate” as people planning for an ordinary retirement at ~65 do, because your fund needs to last a lot longer despite inflation and such. $2m isn’t “retire at 35” (… or 45) money. It might be “take a big gamble and maybe get lucky… for a while” money. Or semi-retire money.
[edit] at constant 2% inflation (ha!) you need a very safe source of consistent (not average!) 6% returns to retire with 80,000/yr income on $2m, without eating into principal. Anything goes wrong (“whoops, ‘safe’ wasn’t as safe as I thought!” or “whoops, we had a year of 7% inflation and my investments didn’t benefit from that!”) and you can find yourself burning principal while your account value is already down. It won’t take a lot of that before $80k is no longer your safe-withdrawal amount. A couple such years and you may be back to work. 30+ years is a long time…
[edit edit] also damn under $10k max out of pocket on a family plan at the bronze level for $17k? I gotta get out of my shithole state. That’s better than our Gold plans (also our plans tend not to cover like 2/3 of area providers, which may include 100% of area specialists for certain situations)