Regulation is a commitment that we prefer "none at all" to the status quo. No more, no less. We talk about regulation creating desirable outcomes, but that's an oversimplification - the ADA does not hire or conscript anyone into the business of creating accessible infrastructure. It threatens that if they won't make their infrastructure accessible, they can't have any. The threat of "none at all" is the whole mechanism.

Which is just fine so long as we remember that none at all is inaccessible to everyone.