You can so easily write (and schedule) parallel dataflows in SSIS, to do the same code using a general purpose programming language would be a lot harder
Also remember that dataflows are data pipe streams, so SSIS can be very very fast
Anyway, there is BIML, which allow you to create SSIS package by writing XML, I personally never used it, mainly because its licensing situation seemed weird to me ( i think BIML is free, but the tool support is not, and MS SSDT doesnt support BIML coding i thinkg)
You can so easily write (and schedule) parallel dataflows in SSIS, to do the same code using a general purpose programming language would be a lot harder
Also remember that dataflows are data pipe streams, so SSIS can be very very fast
Anyway, there is BIML, which allow you to create SSIS package by writing XML, I personally never used it, mainly because its licensing situation seemed weird to me ( i think BIML is free, but the tool support is not, and MS SSDT doesnt support BIML coding i thinkg)