The question I'd ask in reply is...If I told you you were trading for a consistent 3 WAR pitcher, with good playoff experience, but with only 1 year of control and a $9.3 million salary this year, would you give up Dunning+ for that? I wouldn't. He may not have the playoff experience, but even coming off injury, Dunning is a guy who is under team control for 6 years with several games in the majors where he showed he can get big league pitchers out. He would have a legit shot at putting up 3 WAR this year, and Dunning + an extra $9 million to spend would very likely be preferable when you consider the extra control. He put up 0.7 in 2020 in only 8 starts as a true rookie coming off injury.
This discussion started because someone said that the White Sox had paid the price for a 5-7 WAR pitcher, and I think that's fairly accurate. If you told me I was getting a 6 WAR pitcher, with 1 year of control remaining and a $9.3 million salary, I'd say "Yes Dunning+ is a sensible trade for that", you lose a lot of control but your rotation now has another all star who can match up with anyone." So one of a couple things needs to happen - either Lynn needs to be that 2019 version, or the White Sox need to win the world series so that we say "eh Lynn wasn't all that great but who cares here's a trophy."