Unfortunately there is no realistic vector drawing open source app for MacOS. Inkscape is still basically unusable with extreme lag. LibreDraw is ok for very basic things. But that's about it.
?? I use Inkscape every day on macOS and it runs just fine, equivalent to on Windows/Linux. It was pretty bad a few years back but has caught up.
(Houdini is the second-most crashy app I've seen, and it's nothing compared to Inkscape at least on Windows.)
Any idea what the difference is? The cheaper one looks more capable.
Photomator = Lightroom, but without the library management