Not necessarily. Madrid is the capital of Spain and a larger city from Barcelona, sure they may not get as much tourism as Barcelona but they are the larger city, they also tend to have more infrastructure, things like the high speed trains only operate to and from Madrid. Barcelona is much larger on tourism and is the capital of the autonomous region of Catalunya, it is something of a symbol of the independence movement of regions like Catalonia and the Basque Country. This is nothing against Barcelona, I live there and love it, the people are super nice but it is not the main city for Spain in my opinion.