I don’t understand the hatred for select multiple on desktop. It’s a list box that uses standard UI conventions that have been present for three or four decades now.
I use it in one place in my app, and even with me putting text right above it saying something like "ctrl+click to select multiple entries", I still periodically get emails from confused users. No idea what the actual % is, but it's gotta be some non-trivial fraction of people who just have no idea how to use that thing.
They're probably referring to it not being usable without keyboard, unlike regular select, or checkboxes, or anything else sans a text field. Specifically, to select elements one by one, you need to hold down Ctrl (on Windows; modifiers for other OSes are different).
For better or worse, this element is not obvious for those who didn't grow up using desktop computers 10+ years ago.