Yes, DnD rules can be complicated. But I think the bigger problem is that the game does not use DnD rules but a mix between DnD and DOS.
I would say an even bigger problem is that BG3 doesn't explain its rules adequately. - Character creation and tutorial sections are woefully inadequate to explain all things about the D&D 5e + Larian homebrew system that is BG3. - The combat log is not useful: it doesn't record many rolls and those that it does include aren't fully detailed. What are the rolls behind Shove? - There is no in-game rulebook / glossary, combined with the fact that key terms aren't highlighted in item/ability/spell descriptions, etc.
Addressing these would go a long way to making people better understand - and thus probably more enjoy - BG3.
