This looks exactly like `bpytop` which I encountered several years ago and really liked.  But it soon vanished from the Debian(?) repos.  It was written in Python and it was a bit sluggish, so I had mixed feelings and didn't go looking to build it myself.  As it turns out, `btop` is by the same author - which explains the similarity of appearance.  If you look at the two git repos, it looks like `btop` is being worked on and `bpytop` has been abandoned.  Using C++ for this version probably addressed the sluggishness.  Glad to see this is still around (and in the Debian repos), thanks for pointing it out.