Humans are really really bad at undestanding randomisation. Weighting dice is the best way to stop people thinking you're weighting the dice.
The challenge is here that their random number generator (RNG) seems to be off. I cannot confirm the validity of those claims since I have not made the effort to acutally track the rolled numbers. I also have not found an analysis (google) of BG3's RNG.
If you use real world dice you can check the normal distibution for a D6 (or D4 ord D20) yourself easily if you have the time and want to spent the effort. And rolling your own dice probably make you more accepant to the fact that you just had a string of badly rolled dice.
