The design was absolutely used to attract tourists, and each cathedral was competing with all the others for attendence. That's why they were constantly updated, built upon, and in some cases: demolished to start again.

Except those tourists were called, "pilgrims". The money they paid to enter the building was what was used to fund the cathedral itself. See also, the Holy relics, like the Crown of Thorns. It's like a roadside attraction, except there's the hope of escape from earthly damnation and enter into everlasting peace in Heaven. Which I mean, that's a nice bonus. Such promises were made to those who worked on and/or financed the cathedral's building.

That whole system isn't in play anymore (The Catholic Church just doesn't have that power, or Monopoly over things like intellectual property like books and people who can read those books) and places like Notre Dame are in serious disrepair (before the fire). That's sort of the real tragedy: this fire probably could have been avoided if the money was there to spend.