> 90s apps used these Windows handle controls and it was not a performance problem.
For a while there, at least on Windows 3.1 and before, possibly some Windows 9x versions -- you had a GDI heap and USER heap of 64k each (one 16-bit x86 segment). If you allocated too many HANDLEs, you could blow one of these heaps. So it still made sense to be judicious about how many windows you created. Most Web browsers and word processors, for instance, drew their documents in the client area and did not use subwindows to position text elements.
For a while there, at least on Windows 3.1 and before, possibly some Windows 9x versions -- you had a GDI heap and USER heap of 64k each (one 16-bit x86 segment). If you allocated too many HANDLEs, you could blow one of these heaps. So it still made sense to be judicious about how many windows you created. Most Web browsers and word processors, for instance, drew their documents in the client area and did not use subwindows to position text elements.