Or, since you know the start and end sizes of your profiles, you could create two sketches and loft between the two.

In your loft sketches though you would need to leave the recessed channel in the bottom of your part a uniform size between the loft curves since it looks to be some sort of alignment feature, but for the main body area - tapered extrusion or build it from two loft sketch curves would be my approach. Might need guide curves if the geometry moves around in someway that you don't like.