The last person I witnessed use a mortar and pestle was my grandmother, and even she was dissatisfied with how a few grains of coriander might regularly fly off.
But mortar and pestles remain very much on sale at stores and online (and most are not provided with a "safety cover"). This suggests that there is something to them, besides nostalgia.
Now consider a cook who has a good quality blade grinder, a dedicated burr spice grinder for spices (all burr grinders are meant for coffee beans, but it's not a workable arrangement to use the same burr grinder for coffee and spices), as well as a mortar and pestle.
When would a cook reach out for a mortar and pestle rather than an electric grinder for spices and a sharp knife for herbs?