Sorry - didn't mean to insult! I wasn't trying to refute anything, your thoughts are valid! However, they also don't invalidate the OP.Agree or disagree with my points to your heart's content, but accusing me of taking the subject matter personally just tells me you can only refute my case by suggesting I'm responding emotionally therefore not making valid judgments.
Which, in turn, I do take personally -- because it's an insult.
Yes, that is how I do it now (and for the past almost 40 years). However, I, as the DM, like the idea of not knowing. That is why I find this, or something similar, appealing. I only mentioned sandbox because I thought it fit that style more (and that is how we play), not that you needed it.Plenty of dungeon masters run sandboxes just fine via reliable prep and improv.