While yes fMRI lacks temporal resolution, the spatial resolution is way better compared to EEG. You also have the benefit of 3D spatial data while EEG only provides 2D data from the scalp. If temporal resolution is important, MEG can be used and has better spatial resolution than EEG.

Generally, EEG's benefit is that it's cheaper (either in terms of data collection or for showing your method has the potential to be commoditized).