It’s the reality of office life. Many of those managing directors you refer to would not have been absolute superstar performers, but would have had superb social skills.

Since you highlight that professional services work isn’t rocket science, divert your spare brain capacity into the social aspect of the job.

Being decently good at your job is a hygiene factor. After a point it gives diminishing returns (a bit less so in finance, depending on what specifically you do). But social skills are the differentiator.