I used Inkscape on Win10 recently, and also on Kubuntu (21.04 a and 21.10, I think) and the experience was comparable.
I do not like the icon themes now, they're very low contrast and difficult to decipher for me so use the old, colourful icons I'm familiar with. Apart from that and one problem with a dialog not appearing until I selected the option a second time (the XML dialog), all worked well.
I think it's difficult, a x.0 might not be snappy, might even have serious issues, but there's not enough manpower resource to address everything at once, it's going to be incremental. Holding things back would negatively impact the momentum of the project IMO, but yes may benefit an individual.
But I couldn’t even properly switch back to the Win32 theme because of severe bugs that rendered it very problematic on all displays and basically completely unusable after a bit on any comparatively small high-DPI displays like my Surface Book’s. I don’t know if any of these issues have been fixed; I did try Inkscape 1.0 final briefly but decided it was still just too bad compared to 0.92. And now I’m back on Linux and so, like the Inkscape developers, don’t care all that much about Windows any more.
(https://gitlab.com/inkscape/inbox/-/issues/879 was my initial report, including explanation of some of the major Win32 theme regressions. Given the adjacent topic in this thread of GTK 4, the mention of overlay scrollbars in that thread points to a mess too; https://wiki.archlinux.org/title/GTK#Disable_overlay_scrollb... says: “as of GTK 4, the overlay nature of the scrollbars is part of the toolkit.” Ugh, GTK is obviously not interested in being a native look-and-feel toolkit if they deliberately remove the ability to control scrollbar overlayedness at the system level or in the theme. If you require the app to switch it on, it might as well not exist. Sounds like they’re continuing with the sabotage.)