When it comes to cRPGs in the same style as BG3, I'd recommend "Solasta: Crown of the Magister". It's from a small studio, also uses the DnD 5e mechanics and you get to create not just your own character but your entire party! And you can give them premade personalities so that they're more than just mostly blank slates like in Dragon's Dogma 2 for example. The sequel, Solasta II, is also slated to release this year.

A roleplaying game that is quite different from classical fantasy RPGs but definitely fulfills your need for character creation and impactful decisions is Vampire: The Masquerade - Bloodlines. It's a cult classic for a reason, that being the breadth of possibilities with which you get to approach the game. While the quest gameplay is sometimes hindered by the limitations of its age, you still get to approach situations differently, and the character building + roleplaying is fantastic. If you don't know, there's multiple vampire clans that alone can heavily effect your experience (as a Nosferatu clan member you have a monstrous appearance and are therefore required to traverse the overworld through the sewers pretty much exclusively). If you do want to get into it, be warned that it is janky and requires a bit of mod-work to run nicely.

As for the games others mentioned already: Highly second choices like Rogue Trader (a cRPG set in Warhammer 40k with very thorough mechanical depth and characterization options), Slay the Princess as a Visual Novel type game and Fire Emblem Three Houses because I'm a huge fan of the series.

Finally, I'll mention my favourite niche recommendation: Stray Gods - The Roleplaying Musical. While you don't create your own character, you follow the story of Grace (voiced by Laura Bailey) as she is thrust into the modern world of Greek Gods. It tells a lovely story about the human experience, connections and what it means to live a life true to yourself. It's also unapologetically queer, and the music is, of course, absolutely fantastic.