The sharp discontinuity in insurance costs over a single year for many people when ACA went into effect isn't explained by your dismissal.

All the stories I've heard about that came from people with bad insurance (for instance: insurance programs that could rescind coverage if you were diagnosed with something serious, and that functioned mostly as billing processors for routine care, which is where ~none of the expense in the system is). The ACA did effectively regulate those plans out of existence, so if you had one, and relied on it, it raised your cost.

But when we talk about the ACA's impact on cost, we're always talking in a macro sense. Every program has individual winners and losers.

Insurance prices _dropped_ in NY after the ACA was enacted. Not "slowed down the growth" but actually dropped in absolute numbers.

That's because NY had enacted a coverage mandate even before the ACA, so insurance companies were forced to offer policies to everyone. This resulted in a runaway spiral where only sick people were getting insurance.

The ACA forced all large employers to buy insurance, greatly increasing the risk pool.