I recognise their communication value but they are aesthetic disasters (colour, dated cartoon style, cacophony) and they are real lowest common denominator expressions - often the equivalent of a fart noise or a “+1”. To support emoji you hand over a huge slice of product aesthetic and expressivity to something which in all essentials, is very childish.
I looked at reddit recently and all the emoji awards that can even apply background animations like flames gave me the strong impression that “this is not for adults”. For something smaller that might be a fine choice but reddit’s opportunity seems to be much larger as the pre-eminent threaded discussion site across all demographics and if anything I suspect longer form discussion skews older.