Simp: includes connotation of submission to someone/something

Normie: cool-averse, trying not to stand out, passive participant

Basic Bitch: goes out of their way to chase fads, lack of originality

Lot of potential overlap between them, but there are certain nuances to how they’re used. A nerd who does whatever their favorite e-girl streamer commands may be a simp, but not necessarily a normie or basic bitch.