I think if we also look at a proposed legislation unemotionally, it would be understandable that this would not be expected to be done in a single operation, but rather, a concentrated and on-going effort to begin to either decouple the tracking from existing code, or rewrite functionality without the tracking, and that Facebook would be subject to assessments to ensure they are continuing to do so.

I get that likely this very likely means that just burning the whole thing to the ground and starting from scratch for most functionality would be less of a time sink, but the point is more that Facebook actually begin to engage in operations to remove tracking from their infra, not just throw up their hands and say "It'll be too much work!". We can know for sure if it's a new code base that just never had it to begin with, and Facebook was transparent in the migration process.

Regardless, though, I do get that the thrust of your point is that this is not a trivial task.