First up: I love Doki Doki Literature Club and haven't played Dream Daddy yet.
Still it makes no sense to say they are the same 'genre', just because they use the same technical form.
DDLC is surrealistic horror and Dream Daddy is feelgood romantic comedy. You could say both games make statements about the gender politics of standard dating sims, but the way they do that is so different that I don't think they are really comparable.
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