Why? Why did the White Sox do it?
The depth in the minors is weak at the position outside of Seby Zavala, who seems to be the only legit Major League ready catching prospect in the system. I understand the Sox believe in Zack Collins, but there's no guarantee he translates defensively. Smith was a pretty productive offensive catcher and went from a minus pitch framer in 2016 to a guy with an above average clip (1.6 and 1.5 in '17 & '18, respectively, according to Baseball Prospectus).
Going back to 2011, Smith spent his entire professional career in the White Sox system, meaning he has a relationship with so many prospects and arms like Rodon (minimal, but still parts of two seasons in the Bigs), Lopez, Giolito and more. Speaking of Giolito...it seemed the two developed a bit of chemistry last season that resulted in success. Giolito needs every strike he can get. James McCann is not the answer to steal any strikes for a wildcard like Giolito.
I like Welly as one of the two everyday catchers, but James McCann? Really? That's the plan? Help me out here because I just can't get over the decision to DFA Smith.