Indeed. Every real-world practice of development can be placed somewhere on the sliding-scale between Waterfall and Agile.
One of the reasons that waterfall was a reasonable way to proceed was that, in the past, tighter coupling to hardware and longer hardware lead times meant the need to design and specify in advance. This is still somewhat the case where these conditions are true, albeit to a lesser degree.
One of the reasons that waterfall was a reasonable way to proceed was that, in the past, tighter coupling to hardware and longer hardware lead times meant the need to design and specify in advance. This is still somewhat the case where these conditions are true, albeit to a lesser degree.