The point you seem to be missing is that the ADA currently has a relatively limited mechanism for direct government enforcement, because the current mechanisms were designed under the assumption that individuals could also sue to enforce the ADA. Most of the government agencies currently enforcing the ADA only produce guidelines and issue regulations, with relatively few lawsuits originating directly from the government. Enhancing the government’s ability to enforce the ADA requires passing an amendment to the law through Congress to potentially create a new office with enforcement authority (or grant additional enforcement authority to an existing office), and to provide adequate funding so it can keep up with the additional workload. The odds of this amendment being passed on its own are infinitesimal; even if it passed the GOP-controlled House (who would almost certainly oppose it on principle, and even the reps who didn’t oppose it would have far more important issues to spend political capital on), it would almost certainly be filibustered in the Senate, where it would die.

The only way it would possibly pass is if it was attached to a must-pass bill, such as one to address the debt limit or avoid another government shutdown. Even then, it’d be vulnerable to negotiations–it may be included initially, but underfunded or dropped entirely in order to accommodate other, more important goals. Even if by some miracle it did survive negotiations intact, it would then be a constant target for defunding or dissolvement by conservative legislators looking to deliver red meat to their base.

Yeah, in an ideal world, it would be nice if the government took care of enforcing the law. But this isn’t an ideal world. Getting rid of individual enforcement trades a system that produces mostly desirable outcomes and ensures compliance with the law even when exploited by bad faith actors and replaces it with a system that is much slower due to the additional bureaucracy and the inevitable backlog piling up from underfunded and overworked agents, and is also vulnerable to the whims of a handful of extremists, placing the quality of life for millions of disabled people at risk.

That’s why I say the ADA will be feckless without an individual avenue to force compliance: even if the government does take over all the enforcement work previously done by individuals, it’ll be much slower, and the government will be strongly incentivized to focus on large, wide-ranging cases over smaller, individual violations, leaving them unaddressed for years (or even ignoring them outright so they don’t get accused of being “hostile to small business”)