Character progression is really important to me too.
I wish we can become some kind of legendary character in some skills. However, it requires a strong skill feature that does allow progression. ANd Larian, those guys have always be very good at that, giving you a feeling of progression, and becoming very powerfull. I remember fondly divine divinity, (or beyond), when you thought character progression was over, only to discover a whole layer of new godly powers. I loved that.
And keep in mind there will be mods. Mine will be focused on skills, replayability, randomness and world interactions. And the big result will be to gain a feeling of character power, but not only through numbers and items powers, but also through possibilities.
And keep in mind that it is also fun for some people to keep playing, and feel the power once you are at the top.