WinForms provided some responsive control patterns like "anchors" and "dock" properties [0] and other sorts of relative positioning. Some third party component libraries included even more advanced layout controls. A lot of applications would add in imperative code to make up for more complex scenarios that anchors/dock didn't handle well enough. WinForms was still built on the back of pixel-perfect positioning assumptions, so there was always people doing it manually with handwritten/hand-tuned math.

It is something I appreciate about WPF and other successors is that responsive layouts became the default and low level building blocks with "pixel perfect" harder to do and less of an "after thought" on top of pixel perfect WYSIWYG that's easy to get responsive wrong, but even with WinForms people were building responsive apps back in the day.

[0] https://learn.microsoft.com/en-us/dotnet/desktop/winforms/co...