All of the above. If I was forced to use current release AF lenses then I probably wouldn't have tried more than say three of four lenses (i.e. the one that comes with the lens and perhaps, at most, three more) BECAUSE OF COST.
But, legacy manual (and AF) lenses are generally way cheaper and as such I have tried dozens of lenses (perhaps 60 in total) - WOW what an experience!!! I have learned sooooo much about photography by simply trying an immense array of lenses ranging from the really bad to the sublime ......
It is through this experience that I have learned more about the limitations of glass, the camera itself and the need to improve technique. My technique seems to be improving more so by using MF lenses - so I stick with it in the main. Great fun