The perplexing thing last year that kind of get pushed to the side are what you mention. RB and WR room. RB room, we knew was going to be a drop off from Breece, but maybe didn't quite fathom how much of a drop off as a fan base. Also couldn't have foreseen the season ending injury to Brock, which certainly magnified the issue. Silas at his size was never going to be the answer, and Sanders is hopefully going to be better this year, but if not, that's another miss in that room. WR room for whatever reason guys just haven't panned out. We hear about them in the spring and in the fall camps, but then they fall silent on Saturdays then end up transferring.
The TE room also experience a predictable, but maybe not quite so predictably drastic drop off as well. Easton Dean wasn't the prince who was promised. Sounds like they are talking up some younger guys again this offseason though, so perhaps that gap will be somewhat better filled now.