I'm surprised the author didn't list KDE's Elisa: https://apps.kde.org/elisa/ Especially since they referenced KDE when they voiced their wish for Strawberry to be more modernized to match the appearance of KDE's Plasma desktop.
I haven't used it for a while (I generally don't listen to music outside of my drive to work these days), but I remember it being a pleasant replacement for MusicBee when I first switched over to a Linux distro full-time, coming from Windows. The Elisa UI is nice too imo, though it's more of a "native UI" look compared to some of the others in the list, though which style is nicer is up to personal preference.
It may also be a plus to some that it is not using Electron , and uses Qt instead (Well, apparently it uses QML, so still kind-of using ECMAScript/Javascript. But only for the user interface, and not the main business logic.)
I remember struggling with it in the beginning (it has some quirks in the UI and how you configure folders and what have you) but once I got a hang on it it was pretty good
I don't use it much, but for a default audio player for KDE, it's surprisingly slow to open audio file just to play it once (around a second on my machine)
Man QML is awesome, it's all native UI, and since it's not a browser it has a much simper runtime available for the js that you write.