You know, I think this is a very fair question. My opinion is that most of the success of 2019 goes to the previous regime, not this one. The players who were acquired and developed by the prior regime accounted for 28 WAR for the 2019 season. Players acquired from this FO only acquired 15 WAR.* That nucleus of Buxton, Berrios, Sano, Kepler, Polanco, etc was going to win no matter who the FO or manager was. The new FO's main job was to supplement that team and keep that window of contention open longer. I don't think they managed that.
Part of this just goes to what you expected from that core, how much a system affects player development in the majors v. minors.
Lastly, I've pointed out several things that this FO did right. I liked both the Cruz and Donaldson signings. The Berrios trade looks great. The Odo trade was solid and Larnich and Jeffers look like solid MLers. It doesn't have to be all or none but at this point, the FO has had more misses - and, maybe more importantly, failed to have a concrete plan - that makes me think that they are't doing well.
* I'm only looking at players who acquired at least 1 WAR.