Not a lot of Proof
There just doesn’t seem to be a whole lot of actual proof that putting nitrogen in tires is better than filling them up with air. Many car buffs do it, they believe it helps maintain tire pressure longer. But this can be overcome by just checking and maintaining your air pressure consistently. Also, the lack of moisture with nitrogen has been said to keep tires from rusting as quickly, but I can’t remember the last time I had any rust on any of my tires anyway. There are some advantages for Formula One-type racing, but for just driving around town, filling up with nitrogen can be more expensive without a lot of proven benefits.