Bear sex.
The hype for the game only really started with the presentation of that scene floodes tiktok. Before that only rpg gamer were really interested because of the ip.
And Larian kept the hype going by focusing on the sexual content in marketing, making it seem more explicit than it was, and designing the companion to be thirst traps, more like characters in a visual novel, than a rpg. And Larian then reworked the game so that you can experience everything in one playthrough.
And the simplicity and full voiceover also helped. You could read a lot of variations of "After BG3 I tried out <other rpg>, but its so much reading/math/complicated so I stopped playing."
Its quite interesting how full vo made PoE2 into a failure but helped BG3 immensely because of the different target groups.
