I think access to government services is an impoetant part of democracy. Because you have no alternative, they should be Held to higher Standards of privacy. Google doesn't need to know everything.
It would require a dev every time someone wants to track something new.
It would require rerunning ci/cd, testing, qa to bake it in, in case it fails and breaks something.
All of that is hours of resources which translates directly into money.
With GTM, planning still occurs, organization, but someone can try something, have a debugger to iterate on, once done, hit publish. No need for dev, testing, qa, ci/cd time, breaking, reverting, etc.
Third party services that remain involved aren't "tooling". They're part of the final site, dragging in all of that terrible behavior of the surveillance industry. So yes it's reasonable to ask why one should have to suffer that to access a public service and/or by government requirement. If we had a US GDPR and some societal expectation of privacy letting us be reasonably sure those vendors were prohibited from creating surveillance dossiers on us it would be more reasonable, but US "governance" is actually skewed the exact opposite way.