The goal of every company is not to turn around and expand like crazy. Managed decline is actually an important goal because companies exist to give their shareholders a return, not for the sake of existing (of course with Posti and Finnair there are societal goals as well). I would be a pretty pissed off taxpayer if the government hired some pöhinämies to run Posti and invested billions trying to do something outside of the core functions of the company just to have it grow "because companies must grow" (or had some visionary idea about stopping the decline in paper mail).

Finnair is not in managed decline but also in a situation where the goal is to stem the bleeding caused by the closure of its most profitable routes. The goal is to serve a core market profitably instead of contributing another body to the graveyard of boneheaded airline expansion ideas.