It's much easier to see the intangibles. For instance, I'm a fairly senior team member who's a core subject matter expert for a few major things our team owns. A huge chunk of my day involves people asking me questions about them.
In person, it's trivial to see everyone coming up to my desk, hear me jumping into team discussions, and so on. Remote, it's on me to let management know that's what my time is being spent on, and if I'm lying it's significantly harder to verify.
I think what you're using as a positive signal is actually a negative signal. If people ask you for help and >50% of the responses aren't "here is a link to a doc/previous discussion" then you are a bus factor 1. Also, this can all be done with a ping on jira or your ticket manager and easily be seen.
Its far easier to quantify slack thread responses and emails than it is to transcribe and parse the audio recordings from your desk of said conversations.