I think the idea here is to go electricity->heat-storage->heat-usage, using the heat storage to take advantage of cheap renewables that might be otherwise curtailed and to buffer the heat to provide reliability for whatever process it is used for.

Almost any form of energy storage other than heat (i.e. batteries, hydrogen, gravity) would be far more expensive in that use case. By comparison, bricks are an incredibly cheap way to store heat.

If packaged correctly this could also be useful for uses like ovens at industrial bakeries, which have highly predictable energy use patterns.