I would re-frame "is it really worth breaking half the web" as those sites are not compliant to begin with. Nothing in the web standards stack mandates javascript, its an optional feature! Web developers of yore understood that a fundamental property of a properly written web site was to degrade gracefully if javascript wasn't available, but the groupthink of the past decade has chosen weaponized incompetence over doing their jobs and in the process has not only thrown a load of noncompliant insecure garbage out there, but broken a load of accessibility standards, and other things in the process.