Someone dragged my attention to the fact that Raymond Hill got upset (see https://github.com/uBlockOrigin/uMatrix-issues/issues/291#issuecomment-694988696)
This is bad news. This extension is a niche, but very useful. The interface is clearly a UX wonderful design, given the mission it tries to fullfill.
I wish someone is willing to continue to maintain this extension. There is nothing to add currently, but from time to time, there's always something cool to add or fix.

A big thank you to Raymond Hill for supporting a better Web experience, and all people that thought uMatrix was broking their browsing experience when it was the opposite.