The contents are rendered through gtk/cairo which not only goes through https://www.xquartz.org/ but also doesn't use GPU rendering (it was experimental 3 years ago, maybe better now). The main issue seems to be that neither Inkscape nor gtk people have low level Darwin experts or time available to invest in debugging the whole rendering stack. See for example https://gitlab.com/inkscape/inkscape/-/issues/1614 and all the other referenced issues for all the gory details.
This is very insightful, thank you. This might make me switch back to wxWidgets in fact. Desktop GUI is new to me and I have been trying electronjs(too fat), wxwidgets, gtk, flutter, maybe even Kotlin, looks like I will stick to wxWidgets.
