I agree. Blue men are indeed more than due for a change/update.
First, they should look more realistic and not transparent blue. This certainly clearly indicates they are bots but it detracts from the realism of Zwift. Perhaps they could remain blue but give them a full kit so they are not so distracting.
There have been many other suggestions in the past with regards to updating the AI of these bots. I too feel they are placed and paced somewhat random and I almost never find one or more to ride with and I ride a full range of paces on Zwift. It should be much easier to find a group of them to ride with or perhaps they should automatically adjust to ride with you. That could be a preference?
So, IMHO, the blue bots fill up space but that’s about the length of their usefulness now.