Your statement contains a misguided assumption that adoption of Flutter on the web explicitly breaks accessibility; it's no wonder that you didn't receive a response.
Under 15 employees, Title I does not apply to an organization's website.
Above that number, and, provided that it's part of the design phase, ADA Title I and/or Title III compliance can be achieved by ensuring that each element, attribute and operation is sufficiently tagged; this validation can be built into widget testing in the same manner as one might do for React components.
> I don't understand how breaking accessibility with Flutter wouldn't mean that companies that use it on the web are violating the ADA.
And didn't get a response.
I'm still left wondering how a company that adopts Flutter on the web wouldn't be violating the ADA by breaking accessibility.
[1] https://news.ycombinator.com/item?id=26335062