There are always Igoudalas, Livingstons, Boguts, JR Smiths, Iman Shumperts, Tristan Thompsons, Mike Millers, Richard Jeffersons, Jason Terry, Caron Butler, Jason Kidd, Shawn Marion ...
And on, and on it goes.
Every championship team has mid-tier players on sizable contracts. The question isn't whether or not we should/will eventually have them.
There are three real questions about that:1) Is Smart a contending team's mid tier player? 2) Do the Celtics have their cornerstones locked in? 3) Are there other players that can fulfill Smart's role in different ways?
Smart's play-making and ball-handling will be absolutely unnecessary on this team next year.
Smart's versatility on defense will be absolutely unnecessary on this team neat year (quite possibly the most versatile team of all time).
Smart's defense will be missed, but with Brown and Tatum blossoming, Hayward coming back, and CBS to find pieces to plug into a 3/d role (Byrd? Ojeleye? etc.), they can make up for pretty much all of his defensive abilities.
The hustle will be missed, but that can be made up for competitive spirit (Brown, Rozier).
The timely plays will be missed, but that can be made up for with high IQ basketball.
He might be a solid mid-tier player to have, but the Cs are overflowing with legit talent. Overpaying is not necessary.