I was one of them. To me Schwarber in 2021 is a dead ringer for JDM in 2018. He's made everyone in the Sox lineup better, especially in the postseason. Alternating at the top spot with Kike has, I think, really helped Kike. But it's more than that. Against righties JDM is batting freaking 6th with an OPS of 1.310.
The other thing is that, while hitters definitely can have up and down seasons, on the Sox they are usually more consistent than Sox pitchers, especially the expensive ones. Sale comes to mind on the current team, and even Barnes, who went into a tailspin almost immediately after getting that new two year raise in pay. Price, of course, who is still on the payroll.