Man - they were rebuilding in 2017 and 2018. You can deny that all you want; however, avoiding commitments to long term FA's in 2017 and 2018 was part of the rebuild, keeping almost all of our prospects was part of the rebuild, trading veteran relievers and anyone of any value for marginal 'lotto ticket' prospects was part of the rebuild. They have successfully restocked the farm system to the point it's now widely considered to be top 5 in the league.
Keeping the likes of Happ, Martin, Morales, Pillar, etc. in 2017 and 2018, while resigning Estrada, trading for Solarte, etc. was part of the effort to field at least a palatable roster. The plan was to try and remain competitive through the rebuild - however, it simply didn't work (that's baseball). Now that they've dealt all those veteran guys - you can see why they chose that route (because they are all worth next to nothing).
I mean they could have sold Sanchez and Donaldson right after the 2016 season, but you (should) be able to understand why they didn't (actually - I don't expect you to understand). Injuries destroyed that value.
in 2019 they've clearly decided that adding some veterans to try and field at least a palatable roster was no longer worth it. They needed to see what they had in some of these fringe players. You can cherry pick some FA signings and potential trades all you want - but it's pretty pointless. I look forward to your respond, which I fully expect will include a lot of 'I told you so's'.