If we look at the short term, then yes, they haven't been great but they were bought for the long term. So I don't know, maybe we should wait a little longer than just 1 season to judge them?
The problem with buying players that a manager specifically wants is that what happens when the club change manager? What if Player A was bought by Manager A but when the club change to Manager B and doesn't fancy Player A, then what? Then there's also the point about not every manager's targets/signings are great either. Imagine if we had followed through Conte's targets last time and bought some actual poor players that he wanted.
Let's face it, most of the big clubs these days have some sort of transfer committee/sporting director/director of football overseeing transfers. For better or for worse, ours are no different.