I don't think there's any complacency. That implies guys aren't hungry or trying or working hard enough, which we can't know but likely isn't at all true. It's just age, and where it's not age, some players who simply might not to be that good.
And some roster construction issues. Dombroswki and the front office analysts/pro scouts have really managed to botch the same roster spot three straight times now (Harrison and doing nothing at the deadline in 2023, Merrifield and Pache and Hays in 2024, and now Kepler. I'm not saying Kepler is a flop yet, but that should be a RHB).
The other thing is this front office chose to build a team around the old-fashioned maxim, "pitching wins championships." And they might not be wrong, though they're also risked their belief on that on two older players. They could have let Nola go and spent that money on a big bat. Or they could have not traded for Luzardo and spent that money on more than Kepler.
As long as they are in striking distance of a WC it's still a go for it season and anything can happen, especially with that pitching. And if it's a disaster season, that would be somewhat clarifying too. A lot of baseball left. And not even hittin' season.