In most big companies in Silicon valley, being a manager is not a promotion but rather a parallel track.
What I find strange is that most of big cos expect managers to not be technical anymore. There is that weird expectation that the manager should have been technical in the past but is now only used as an enabler for the team.
Even in silicon valley this is largely the minority. Yes it does occur more frequently here but not to any scale worth noting.
It is part of human nature for leads to gain more than the fair share even when the leads are doing disproportionally less work and less skilled work. This has happened across the board for almost every culture past tribal cultures.
What I find strange is that most of big cos expect managers to not be technical anymore. There is that weird expectation that the manager should have been technical in the past but is now only used as an enabler for the team.