A team getting to 100% test coverage and enforcing it feels like an application of Goodhart's Law.

When a measure becomes a target, it ceases to be a good measure.

At my last job, we required 100% code coverage for most code, and the other parts of the code (in ideality) were marked with ignores that were well-thought-through.

In practice, I ended up writing a bunch of test cases only to hit the if blocks. It didn't mean that the tests I wrote were any good. I'm still a fan of 100% test coverage, but with some leeway for what needs to be ignored, and what needs to be tested later (non-critical paths, if you have a deadline, perhaps)