>>544525592
In the case of Vegeta fighting cell, it was Vegeta wanting to pure beat down cell and dominate the fight. Saiyans do like to fight in the sense that they like to beat people up and win. Goku likes to fight for the sake of the fight itself. Of course he'd prefer to win, but it's not that important to him if he loses, unless he's about to die or something. Given how the usual plan was just to instantly nuke a planet with Oozaru, and how power levels at birth matter the most out of anything, I can't really fathom that fighting to get stronger is all that important for most saiyans.