Are managers becoming disposable leaders ?

It's a thought, it is a feeling, but organizations-an-sich, especially clusters of collaborators seem to become more time-dependent, limited in time, often just temporary mini structures that cease to exist after a specific task has been done. This also has an impact on the role and life cycle of managers within a company. Managers are experiencing nowadays what football (soccer) trainers already experience for years. They all have a short lifespan in a company or club. They are replaceable assets. They come and go together with new 'momentums'. No reason for leaders and managers to create or even follow a longterm vision, .... ?
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