As I understand it, FIP excludes balls in play, which I think is dumb.
Last night, for example, ERod gave up 11 hits, including 4 doubles, which, according to FIP, are utterly meaningless and inconsequential. On the other hand, he had just 1 BB and 6 K's, so, according to FIP, he pitched a whale of a ball game. That is just crazy.
I personally think ERA already favors pitchers too much. For example, if a pitcher makes a really dumb error and that results in 3 runs, they are all unearned because his fielding is irrelevant. If a pitcher simply doesn't cover 1b on a routine grounder to the right, and the batter gets on base, that is counted as a hit.
So to me his ERA of 4.70 speaks volumes about where he is this year.
I think ERod's pitches this year have all been suspect. Last night, the changeup looked pretty good, but wasn't always in the best spot and probably wasn't used enough. His fastball and cut fastball are both very hittable unless outside the strike zone. The slider might be OK, but it breaks in on righties (the Jays had 8 in the lineup last night) and therefore needs to be low and/or hitting the edges of the strike zone.
In his defense, he was pretty darn good in 2019, and last year he had COVID, which affected his heart, which seems to me to be pretty serious. Coming back from something like that can't be easy. Didn't he also report a "dead arm" right before the season started?