What mechanism is the source for Earth's Nitrogen? - eviltoast

I recall an explanation of the formation of Jovian moons on the Harvard Smithsonian “CfA Colloquium” YT channel that casually mentioned how various elements freeze out of the solar wind forming ices, and this is the mechanism that allows formation of moons with large amounts of water and elements that are not found in larger quantities within the inner solar system.

I will admit I have a strong bias where I want to believe Theia was an ejected first generation Jovian moon. I don’t like the idea of planets (Theia) forming around Lagrange points as it feels like fitting a theory to the evidence. There is apparently evidence of an earlier generation of Jovian moons and it is the most logical source for such a rogue object traveling slow enough on the solar plane.

With that aside, Earth’s large amount of nitrogen in the atmosphere seems weird. Not that Earth has it as much as why Venus and especially Mars do not. I understand Mars lacks the gravity to hold onto gaseous hydrogen that is stripped away by the solar wind over time, but it can hold onto carbon dioxide. So shouldn’t Mars hold onto nitrogen too?

IMO scientific explanations of Earth’s formation seem to lack the broader perspective of Earth among the solar system as a whole. Earth should look like a Venus:Mars hybrid. Theories seem to start with Earth as a baseline and explain away Venus and Mars as exceptions. It is like we are taking a sample size of 2 and throwing it away in favor of a (much more thorough) sample size of 1, when that sample of 1 has an enormous error source in orbit around it, which most old theories have simply ignored. Like the water isotopes on Earth do not match the comets/asteroids theory, but do match a Jovian source.

So how does Earth acquire a bunch of nitrogen when it is well inside the nitrogen ice line of the solar wind and how does this account for Venus and Mars?