Ask HN: MacOS Wi-Fi Diagnostics files were the culprit. What's next?

Recently I have been constantly getting a low disk space alert by Mojave.

In my quest to handle the issue, I desperately removed many applications and moved so many files - most of which I have to use daily - to an external drive. But the problem resurfaced again shortly after, leaving my utterly helpless.

Until I realized that almost 2 GB of my 128 GB disk was taken by Wireless Diagnostics *.tar files. (each file is between 140 MB to 240 MB). Strangely, macOS's new storage management system doesn't suggest to remove these files, but has no shame telling me I have to remove my client project in xcode...

That is plain crazy. I wonder, what other files does macOS produce that could be safely removed? As a starter, I have decided to remove many binaries and libraries installed via "brew" and "Anaconda". For example, if don't use Ruby, why on earth should I have it on my Mac?