Solasta has deeper and consistent mechanics that works as a whole. It makes you live a journey accross it's world rather than throwing you "fun gameplay" on your face everytime for the sake of it. Despite the size of the project and the custom world, Solasta is far more like BG1/2 than BG3. The only things it lacks is freedom and a deeper story.
Which are the two things that made the original saga, imo. BG1 and 2 were never about tactical combat. There are some amazing mods that can increase the challenge, but "out of the box" both games are very easy. What both BG1 and 2 offered instead was the freedom to go and explore the world. Whether you focused on the main quest, or went off the main path - that was up to the player.
