My take on the plots of WotR and Kingmaker are that yes, the actual plots are straightforward, but that straightforwardness is in service to you just being able to experience the world and events. The appeal of the game is the journey, not the destination. It's seeing how the mythic paths impact you and your experience, in interacting with people and quests and seeing how those change things, seeing how your choices can change things, and seeing how all the events and occurences change your character. In Kingmaker, the plot is, I would say, even more basic than WotR, but I think structurally it works almost better than WotR, even though I like WotR way, way more. Kingmaker is about being the ruler of your barony and the choices you make as a result. I would argue that the overarching plot is way less important than the small plots you get involved in each chapter, and the overarching villain really just exists to facilitate those smaller plots. You don't even really make moves to solve or directly address the main plot until pretty late in the game. But you know what? I FELT like a ruler when I played it. I felt like my decisions had weight and influenced people, and I was so excited whenever I had a stretch of time to just do nothing but rule and play in kingdom management. I feel like those games aren't interested in telling you a story so much as they are interested in letting you make a story. Despite not really being an open world game, I genuinely think it's a structure that should be the default for any open world game, because it encourages and rewards taking time to just...adventure and do stuff.
After my most recent playthrough of WotR, when I finally completed the secret ending for the first time, I actually went to the pathfinder wiki and read up on just what it means to
be a demigod. I even wrote out a word document expanding on what worship of my character would look like, what her domains would be, sacred colors and animals, etc. Even a little bit on how she would impact the history of Golarion.
The game felt so much more personal to me because it actually felt like MY story. Even playing two iterations of the same mythic path felt meaningfully different because I had freedom to play out the arcs of two different characters going down the same paths.
If that style of storytelling isn't for you, I'm not gonna cast judgement, it's not for everyone. BG3's story, I don't think will be for me (mainly because I think it's poorly told rather than because of any style issues, but that's another topic) but I do think that if we're going to compare the games, then it's worth acknowledging that they aren't trying to tell the same kind of story. BG3 is clearly more focused on the plot as the end goal in the way Owlcat's games aren't, and that's, if not the strength of the games then what I really am drawn to about them.