I think it also depends on how people think. I might be able to sit can't sit in a meeting room/white board/documentation editor and come up with what the big problems is (where pain points in implementation will occur, where a sudden quadratic algorithm pops up, where a cache invalidation becomes impossible, ...) even if I stare at this white board or discuss with my peers for days.

But when I hammer out the first 30 minutes of code, I have that info. And if we just spent four 2-hour meetings discussing this design, it's very common that I after 30 minutes of coding either have found 5 things that makes this design completly infeasible, or maybe 2 things that would have been so good to know before the meeting, that the 8 hours of meetings just should not have happened.

They should have been a single 2 hour meeting, followed by 30 minutes of coding, then a second 2 hour meeting to discuss the discoveries. Others might be much better than me of discovering these things at the design stage, but to me coding is the design stage. It's when I step back and say "wait a minute, this won't work!".