If I may humbly weigh in on this...

It's not just about the code, it's also about the culture.

Non-performing staff could be non-performing for different reasons - not just output - and it's often easier to spot those reasons (and address them) when you're working in the same office.

Source: I've been running a company with hybrid in-office + remote staff for 15 years. Would be happy to expand on the above if asked.

15 years of experience with this kind of work puts you well ahead of most, so I’ll bite: please do expand on the above :)

I take it you're not a professional slacker. It's so easy to game all these tracking systems.

People who consistently deliver code and working features usually don't have a problem getting approved to work remotely. That's the case-by-case part. It's the people whose code is buggy or nonexistent and whose features don't work that are stuck in the office.

But what is there's no code or code that is not used in a working feature? Both ends of the performance spectrum comprise people who don't really code.

You've just explained it yourself: there may not be enough code and/or working features.