Clearly the angle at which planes take off and climb depends on lots of things (mountains, residential area, aircraft type, wind) but when watching planes take off after another from the same runway, I have the impression that similar aircraft climb at different angles right after another.
So I'm wondering it this is a measure to increase the distance between two planes quickly after they leave the airport? Such that every other aircraft is asked to leave flat'ish (within what the plane and regulations allow) and others more steeply?
The question occurred to me at GVA (single commercial runway).
This is about the initial climb angle, not their course heading.