Cancelo has admitted he has issues. It's not like he isn't aware. That being said, & considering he has the wherewithal above most people alive to seek the very best professional help & support, where does sympathy come into it, over & above a level of self responsibility?
Stones, Gundog, Rodri, Philips, Sterling, Jesus, Zinchenko & several others have also had periods being out of the team, but they respectfully spoke to the coaching staff to see what they should be doing to force their way into the starting line up, & if that didn't work, they & the club parted company.
By all accounts, Cancelo's way of dealing with being being dropped because of a lack of form was to launch into a suicide tackle on Foden in training, causing an injury which apparently led to a training ground fight, with the injury keeeping Phil out of the team for weeks.
Now just imagine if that's how the rest of the players reacted to being dropped? Are you OK with that?