> An ineffective manager may enforce ridiculous deadlines coming from upper management
This is not how it works in modern workplace. In large companies the pressure mechanism is delegated to a whole group of employees in the same place in the hierarchy - POs, PMs, Scrum masters, various process lunatics. In case of problems they feed the line manager with negative feedback thus creating an image of bad team player, the line manager itself is a divine being rising concerns at most during friendly one-to-one conversations. Once it's clear you are not a good team player, it's better for everyone if you'll be let go. Ideally this process should be catalyzed during the trial period.