Sagrada Família is an amazing building. Going inside it is an awesome experience.
But it is a _lot_. Putting aside the artistic skill and construction cost of it, I'm glad I don't live in a city where everything is like that. I feel like it'd be overstimulating much like an analog version of the Las Vegas strip.
I live in Barcelona, it's a very pleasant city (if you can aford to live here), The city has almost 2000 years of history and architecture. It's inhabitants left its mark. Eixample (the Extension) was planned kinda all at once by Cerda and thats why theres an over representation of specific styles of architecture, and why Eixample feels a bit like an open air museum.
https://www.youtube.com/watch?v=YfN517mqhC8 (Absolutely worth watching if you want to know why Barcelona was planned the way it was.)
If you go to the "Gothic quarter" or to Gracia you won't see much "Art nouveau."
Its a very varied city. I live in a building in the "Modernisme" style and its lovely.
Did you visit other Gaudí buildings? La pedrera is open for visiting and a very nice apartment building. I wouldn’t mind a city where most buildings are like that.
Sagrada Família is very purposefully a total exaggeration but so are most large churches when viewed as part of their surrounding context. They’re designed to stand out.
It’s no different from living in a beautiful natural landscape. I can tell you from experience that no, you get used to it.
It would not be a lot. It would fade into the background, except that any time you want to see beauty you just have to look up and focus.
The level of detail can vary while keeping the idea intact. You wouldn't be more overwhelmed than when you walk down on any european old city centers.
Compare Sagrada Familia to Times Square.
I used to go past it everyday and eventually you don't even bother looking up every time. I don't think you meant it as your point, but I do think Barcelona lacks the nature/parks inside of it that can help with that though (I'm aware spaces exists, but in tiny patches for a large proportion of it).