I was going to say that they probably borrowed the dock from NeXTstep but now I see initial release of NeXTstep was 1989 while initial release of RISC OS was in 1987 ("Arthur") and already had a form of the dock, or at least a dock-like launcher.
https://docs.microsoft.com/pt-br/archive/msdn-magazine/2009/...
The chief difference between the Windows task bar and a MacOS dock is that some subset of icons on the dock are present even if the application hasn't been started.
You could not pin icons to the taskbar in Windows 98, no.
Windows 98 integrated IE4, which contained a feature called "Active Desktop".
This was not a Win98 innovation -- if you installed IE4 onto Windows 95 or NT 4, you got the same features.
Active Desktop included dockable "toolbars" that could be pinned to the desktop or to any edge of the screen. One of these became part of the taskbar, and was called the "quick launch" bar.
It's a separate area for program icons. If you launch an app, you end up with _two_ icons: one in the quick launch bar, _plus_ an icon in the taskbar as well.
The Quick Launch toolbar is still present in Windows 10 today, in 2020, and can be turned back on very easily: https://mywindowshub.com/add-quick-launch-toolbar-windows-10...
Pinning launcher icons directly to the taskbar was a new feature in Windows 7 and was not possible before that: https://social.technet.microsoft.com/Forums/SharePoint/en-US...
It was really quite a lovely system (very few installer programs, install/uninstall very clean with minimal dependencies), but it managed as well as it did mainly because nearly everything was statically linked and did its own thing for config. So centralised management of preferences was difficult, and what shared code there was (like the C library) broke the model a bit by needing to be kept in a separate '!System' directory.
As systems got more complex and ended up on the Internet, there was a greater concern for shared state between applications and security. Consequently the amount of stuff that started from disc on startup, the number of shared libraries and config files etc. went up, and some of the advantages of booting from ROM and the minimal 'copy to install' model went away a bit.
No, not really.
Remember that Windows 1.0 was a primitive sort of tiling window system, because Microsoft was afraid of being sued by Apple and did not dare implement overlapping windows.
What you are seeing is a strip of the desktop background, which contains icons representing running programs. The tiling algorithm leaves a strip of "desktop" visible so that you can get to the program icons. This is how you switched between programs.
Windows 2 reintroduced tiling windows, but had no desktop icons as such -- again, it was afraid of being too like classic MacOS. This meant that you could rearrange windows, and so see the desktop. That in turn made it clearer that programs minimized to the desktop, as nothing else could be on the desktop.
This can be seen clearly if you look at screenshots of the work-in-progress test versions of "Windows Chicago", e.g. https://sites.google.com/site/chicagowin95/index -- this is what was to be Windows 4.0 but was renamed Windows 95.
For instance, in this one: https://sites.google.com/site/chicagowin95/index/chicago40
... you can see some running program's icons sitting _on top of_ the prototype taskbar.
There was no separate container for program icons. The taskbar was invented _de novo_ in Windows 95, and subsequent to the invention of the taskbar, icons representing running programs were moved into it.
While Windows 1 tiles might have been due to wanting to avoid upsetting Apple (though in terms of APIs and resource management it was mostly a copy) there were those who preferred tiles like With's Oberon (which I also used at the time, along with GEM and Geos).