I don't think they're hurting as much as they're creating a symbol
I think it would be naive to think these people care or give a fukk about Charlie Kirk - they do, however; understand the importance of having martyrs and how they can be used to radicalize and further spread their agenda. Dems are still trying to figure out how to go viral, whereas these dudes all but own social media platforms. Twitter is literally nazi land and the place they use to organize, lie and spread their messaging.
The average individual is incredibly dumb, don't underestimate how idiotic people are, and will feel how they're told to feel - so if you turn Charlie Kirk into a martyr - rather than actually looking up the piece of shyt he was - the average individual will look/aspire to be like him ("well, everyone admires him and says he's a good guy"/"he was a christian following the word of the lord" etc) and align themselves with the movements and messaging that cac was pushing