These four books nail the ACOTAR vibe in different ways, but they all have that same pull. You start for the world-building and stay because the romance got under your skin.
The Cruel Prince by Holly Black is probably the closest thematic match. Jude is a human girl in a fae court, surrounded by beautiful, dangerous immortals who want her dead or, worse, want her. The fae politics are relentless. There's no safety net. Black doesn't let you forget that these creatures are fundamentally alien, even when you're rooting for the romance. The court intrigue scratches the same itch as Prythian's political maneuvering, and Jude's relationship with Cardan has that slow-burn devastation that makes you reconsider basic human morality.
The Serpent and the Wings of Night by Carissa Broadbent strips away some of the epic scope but cranks up the intimacy. It's got vampire courts instead of fae, but the vibe is similar: a girl in impossible circumstances, high stakes from page one, and a love story that feels actively dangerous. Broadbent writes romance with teeth. This one moves faster than ACOTAR but doesn't sacrifice depth for speed. Kingdom of the Wicked by Kerri Maniscalco is for readers who loved the demon/dark love interest element. It's set in a historical fantasy world with witches, demons, and a heroine who's clever enough to match her dark love interest's wit. The banter feels earned. And Fourth Wing by Rebecca Yarros gives you that slow-burn enemies-to-lovers with a protagonist who's smaller and more fragile than her peers, forced into a cutthroat military academy for dragon riders. The dragons themselves are characters. If ACOTAR made you crave that 'she's tough but not invincible' dynamic, this delivers.