What matters is what level he plays at, what the Steelers would be willing to trade him for and the cash paid out to him in future years which is (according to spotrac)...
2019: $15.125 million
2020: $11.3 million
2021: $12.5 million
If he's healthy, and not a huge pain in the butt for the locker room then he is probably worth it...
The next question is what would the Steelers take for him... when WR Santonio Holmes got it in trouble (a different kind of trouble) they traded him for a 5th round pick, which ironically they traded down for a 6th round pick which was used on Antonio Brown.
Though that was after Big Ben's legal trouble and they wanted to make an example out of the next person that screwed up, and Holmes reportedly pissed off ownership and was gonna get released if not traded. So this could be a different situation.