Xolvixica
Perhaps the slider works differently on Linux with its sound subsystem, or maybe this was an issue with older versions of Audacity. Googlign does suggest that the Audio host option on the toolbar, if the "wrong" one is selected, could result in the system volume being directly modified by the slider (https://manual.audacityteam.org/man/device_toolbar.html)
Anyways, maybe just look into that. In my experience people prefer to whine and whinge rather than solve their problems. Take that as an insult if you want (not intended), but if it helps resolve this issue for you then I don't mind.
Unpack the RAR file somewhere, open the configuration tool inside, configure as desired but ensure the "Show details pane on the bottom" is enabled. You'll then get an explorer that looks very similar to the Windows 7 style, complete with the exact same Win 7 details pane which frankly is a lot more useful than the basic one in Windows 10.
I know it's being worked on with Firefox having acceleration worked on in Wayland, but right now, if even the simplest and most common use-cases have major downsides compared to Windows/OS X, it's hard to justify moving to a worse experience. Windows rules with vendor support, that's just how it is. I've grown tired of having to compromise.