im a cease fan so im not gonna horsefeathers on him (and im not gonna defend jed or ricketts, but i can see the vision here), but he's thrown 900 innings in the last 5 years. Sure, you can look at that and say "wow he's durable," but in a world where no pitcher can actually be durable anymore, you can also look at that and say "wow that elbow's about to blow."
You (not you, you, the royal you) really just have no idea anymore. The only certainty is that every pitcher breaks at some point. Maybe Dylan Cease has the magic mechanics, or maybe his elbow snaps like dried spaghetti in spring training.
So you can spend $210 million and commit 7 years to Cease, where it is a near certaintly he breaks at least once during that contract. Or you can get a guy who is arguably just as talented, who costs you nothing more than 2 lottery tickets and a ginger 4th OF, and you only commit 3 years to him, so if he breaks, it's not nearly as catostrophic.
And of course the probably most important element of the calculus here is being ignored - if the $30m they would have had to spend on Cease instead get spent on Bregman/Bichette/Tucker/Whoever, it's an enormous win, and a smart bet on upside considering all pitchers are essentially walking timebombs anyway.