Yer, he's not been a happy bunny for a couple of years now so I'll wager it's time to hang up his cycling shoes.
Just an opinion but his unhappiness is his major problem, sure age, ability and physical things like injuries are major factors, but him constantly saying things he couldn't do for whatever reason is a major issue.
Within a team, top down when you have a rider who is constantly giving bad vibes there just is no room regardless of talent. He has a long laundry list of complaints and excuses, just never giving the feeling of an upward, onwards, positive trajectory.
Even now his status, unlike all other top riders is a mystery. No upbeat social media posts about positive things, look at my training, look at me not training, vacations, enjoying family, in the gym, out with friends, ect. Look at majority of cycling success stories currently much of it has an element of positive affirmation, reinforcing statements about self, team, training goals, future. Caleb is doing little to nothing to build strong team and mental support structure..He is only 30, and certainly amongst sprint specialists he can get over rollers as good as 75%..is he a climber? No
but he could be useful to a team or set realistic goals.