No, Spain and Britain are countries. They have a national identity, a flag and a shared culture, even if there are some regional differences. The idea that they are all seperate countries in a union is a narrative petty nationalists like to push to generate grievance and push the idea of shattering the country into fragments.
No different than Belgium with the Flemish and Walloons.
the Catalans have unfinished business with the Caudillo.
The Basques having a territory that transects the Spanish French border, separate culture, unique language and ancient presence have the best case for independence.