It took Araki till party six to give Dio a character. In one chapter Dio has gone from cardboard cutout of a villain, into your quirky and interesting gay boyfriend.
At least he got around to fleshing out his personality more. He was never the stereotypical villain though, he learned from his mistakes and never underestimated his opponents, either.
Now I'm looking forward to Survivor being animated. It pushes regular humans to their limits and makes them a threat to stand users. Seems like end of 2020 at the earliest based on the last two parts.