Wishful thinking. The Catalans want independence from Spain, not from the EU. Most of the Catalan independence advocates want to remain in the EU (even though the EU opposes Catalan independence), albeit as Catalonia rather than as part of Spain. They resent rule by Madrid but not by Brussels, and reject "Spanishness" rather than Globalism. That's why I can't bring myself to be too enthusiastic about their independence movement, any more than I can bring myself to support the anti-London but pro-EU (and pro-immigration) Scottish independence movement.
One way of looking at Catalan or Scottish secession from Spain and Britain, respectively, is the general principle of governments that are smaller and thus closer to the general public. Catalans and Scots are politically to the Left of Spaniards or Britons, respectively, so independence would mean that Spain and Britain would become more moderate politically. The same could be said of a California or Northeastern secession movement, vs. the United States as a whole. Our country, minus California and the states north and east of Pennsylvania, would be more conservative.