The spitfire is just a completely +1 in design over all the other prop driven fighters of the era.
Its spectrum of potential is much much greater as a dogfighter, and if you have watched bruv fight in it, you can see that plain as day.
Its easy to grow into, but hard to fill. It seems like a bit of a paradox at first, but its as simple as that. The design has everything to take fighting to the next level and that is why it seems easy for newbies to get kills in it.
Its not like someone who tries to fly a zero just to get the 1 up satisfaction of turning inside an opponent of American Iron, that is flying with intent, the spitfire doesn't have that, it just is and isn't apologetic about it.