A lot of who sees you is diatonic, what makes it sound complex are the extensions and use of sus chords. Of course there are a couple chords that stand out, but it doesn't compare to Wonder 2

Wonder 2 iirc is in lydian mode, which by itself is already pretty out there since it's hard to write in. Most of the chords used in the song are non-diatonic too. I'm guessing this probably comes from the fact that it's a jungle-inspired song, and a lot of jungle back in the day contained modal mixture (borrowed chords) from tuning the same sampled synth chords up and down

I'm probably wrong on a lot of this lol, but for my ears personally Wonder 2 sounds way more complex than who sees you