Of course people are questioning Pearce's contributions this season. He has been terrible! No doubt the Sox are very aware of this. Teams don't typically cut bait on players after 99 PA, though, so claiming that Pearce is as good as gone needs some actual argumentation beyond that he's been bad. What do the Sox gain by straight up cutting him? Is that gain worth the opportunity cost of seeing whether Pearce can recover and be productive again? That's the case you have to make in order for your assertion to add anything to the discussion.
It doesn't take much effort at all to pull up some information and try to put together an idea of what is going on with Pearce this season. Maybe that will be illuminating. Here's what I found:
Overall, Pearce's statcast components aren't that different. His 2018 was a bit of an outlier for him, with a 11.4% barrel rate compared to a career rate of 7.7%. His exit velocity and launch angles in 2018 were 89.4 and 11.9 respectively. His barrel rate in 2019 is so far the worst of his career at 5.1%, but his angle is 12.8 and average exit velocity only down slightly (88.5). His hard hit % is down to 33.9% compared to last year's 39.2 Most alarming, however is his massive increase in K rate (16.3% to 31.3%) and drop in BB rate (11.6% to 7.1%). The K rate is way, way high compared to his career average (19.8%).
So those numbers are a bit of a mixed bag. His K and BB rates are very screwed up and his hard hit % is down quite a lot, but his exit velocity looks OK.
His batted ball profile is actually improved from last year, with his LD% up from 20.5% to 23.7% and his GB/FB down from 1.22 to 1.14.
Drilling down further, I think we can see the roots of the problem. Pearce's O-Swing% is up from 24.3% to 29.7%, his Z-Swing% is down from 69.5% to 68.8%, his O-Contact% is up from 57.1% to 57.8% and his Z-Contact% is down from 87.7% to 77%. Pitchers appear to be pitching him more aggressively as well, with a Zone% increase of 4.4% and an F-Strike% increase of 5%.
I think these basic numbers explain what is likely going on with Pearce. His biggest problem is his massive increase in K/BB, and this is largely due to Pearce missing a lot more in the zone while pitchers are increasingly working inside the zone against him. When they do go outside the zone, Pearce is chasing more. Oddly his is making more contact outside the zone, which, when combined with some bad luck, results in a weaker batted ball profile.
As far as pitch mix goes, Pearce has faced fewer fastballs (-5.7%) and changeups (-3.4%) but more cutters (+8.2%) and sliders (+2.3%). Note that those % numbers are the increase in % of his total pitch mix faced. In terms of % increases, he's facing 274% more cutters this year than last.
It's also worth noting that opponents are shifting on Pearce far more this season (up to 39.4% from 17.5%) and his WOBA against the shift has been terrible (.121). His WOBA with no shift is down from .393 to .294 but his WOBA with the shift is down far more -- from .329 to .121.
So it looks like Pearce is struggling to adapt to a new pitch mix and new defensive patterns with resulting massive increases in K/BB and far worse results against the shift.
I think this is a reasonable hypothesis as to what is going on but I don't really know enough to have any explanations as to why it's happening. Is it that Pearce suddenly can't hit a cutter and the league knows it? Did Pearce dial up the aggression only to have it backfire? Is there something wrong mechanically that is opening holes in his swing, or is he just not recognizing pitches for some reason? Has he not had time to adapt to the increasing use of the shift against him?
Whatever the cause is, I'm sure the Red Sox are looking into it. There's always a chance that the problem is something that can't be fixed (age caught up with him and eroded his skills past a critical point), but there is also a chance that it's something fixable. Personally, it seems to me that there are good reasons advocate for either side of that argument. On the one hand, he is old and it's very possible that his basic skills have reached a point where they can't keep up with the pitch mix that he is facing. On the other hand, 99 PA is not very much time to adapt to a radically different pitch mix and defensive alignment. With a better approach, I can easily see him adapting and becoming useful again.
If you're going to try to make the case that the Sox should cut this guy now, I think you really need to show your work. Why do you think his struggles are ones that can't be overcome? Make that case and add to the discussion.