There's a line in The Office: "Not everything is a lesson Ryan, sometimes you just fail." I really wish I could get other baseball fans to internalize this. I'm not sure why we'd weight the last two weeks more than the previous four beyond just being irrational fans expecting the sky to always fall.
There's two things going on with the offense, neither's especially concerning. 1st is that the luck with runners on has regressed very quickly. The team was stupid lucky driving runners in the first month of the season, and that has finally corrected and corrected hard. But holistically the team's right where it should be. They've scored 169 runs, while Baseruns (which attempts to strip out luck and sequencing) says they "should have" scored 172. That's essentially a rounding error.
The second is power. Power is incredibly streaky, and unfortunately EVERY SINGLE WINTER baseball fans collectively forget this information. It's like that Patrick Star meme. Through the Padres series, the Cubs were 6th in HR/FB rate, about 3% higher than the league average. Since the start of the first Marlins series they're 24th, about 3% lower than the league average. Power ebbs and flows, this stuff happens.
Like yes please continue with the plan to play more Morel and Mervis and less Mervis and Madrigal, but really all that's "wrong" right now is the baseball gods decided to cram a month's worth of offensive regression into about 10 days, and it came at a time where we played a bunch of tight games so those marginal runs were really felt. But like there's not any real takeaways that would stand up to much analytical rigor. Sometimes you just fail.