Well, sure, 7th out of 14th in NL is literally middling, but they are 13th out of 30 in MLB and 12th in OPS. That's not too far off from the top tier. I believe they were Top 10 and possibly even Top 5 at the end of May. Obviously they feasted on some bad teams in May, but they also lost Harper in June, and he hasn't been himself all season. There's no fix for that really.
I agree the offense has to be better, and I hope they are able to find another bat to replace Kepler, but they are working with what they have, and such hitters as Trea, JT and Nick have actually adjusted. That doesn't mean they will never swing at bad ptiches, but they aren't doing it as much. They're just not as good as they were when they were 28, and this team was built around starting pitching because of that.
I'm still not sure I buy that it gets harder in the postseason. The Mets didn't have an elite rotation, and we teed off on Arizona's best pitchers too. Our own starters and our bullpen ultimately floundered in that series as much as their pitchers shut the offense down [though in the end it certainly did]. LA did not have an elite rotation last year either. The Phillies currently have winning records against a bunch of playoff teams and losing records against a bunch of others. You still don't really know what's going to happen in a post-game series. And MLB playoff history is dotted with guys who were barely Mendoza Line playoff hitters until they finally had that one good series in theirs 30s. Nick is still that same guy who can carry a team for one game or one series and then lose one for you. That's not gonna change. And neither is the fact that as Bryce goes the Phillies go.
In the end of course, it comes down to, what do you invest in this season and roster, though there are so few bats available it might not matter anyway.