It is legitimate to wonder why there is Tree when TreeView already exists.
Let's do a little genealogy to get some context before answering.
Well, Tkinter is the standard Python interface to the Tk GUI toolkit.
In the face of the competition, Tk guys added a new set of widgets: the famous Tk themed widget (ttk).
It was not just an increment like 1 + 1 = 2 but rather a new direction slightly different from the old one without loss of compatibility of course. This document is great to go deeper in the topic: https://core.tcl-lang.org/tips/doc/trunk/tip/48.md
I wanted total consistency across Pyrustic's components, so I decided to stay on the original tk widgets.
Of course people still can use tkk, but Pyrustic Widgets don't use ttk at all.
I also designed a nice to use theme/style system to convince users to follow my way and I find that the visual is not so bad, maybe even too charming ...
Also, how is the support for windows? I couldn't find any mention of it.
A last note, if I may, is to put more time into the github README.md. That's where I usually go to read all the important technical details.