I agree with your comparison with Boderlands, But I also think XIII[1] was a pioneer of the said effects in a game(or at least from the ones I've played in early 2000s).
Arcane had similar impression on me as 'Spider-Man: Into the Spider-Verse' did in terms of animation quality perhaps Arcane is even more visually appealing considering a personal bias for steam-punk(Arcane-punk seems to be a term now); Sound Engineering is great too.
Are we just talking about cel-shading here, or something more specific? cel-shading goes back at least to Jet Set Radio in 1999 (https://en.wikipedia.org/wiki/Jet_Set_Radio).
Arcane had similar impression on me as 'Spider-Man: Into the Spider-Verse' did in terms of animation quality perhaps Arcane is even more visually appealing considering a personal bias for steam-punk(Arcane-punk seems to be a term now); Sound Engineering is great too.
[1] https://en.wikipedia.org/wiki/XIII_(2003_video_game)