Patronage and support of the arts (and sciences) was a great value proposition for Churchmen in old times. You could commission works of music or sculpture or stained glass or what have you, and these were of course well-fitted to be installed or performed in the confines of your church and serve the liturgy. So they were
collective goods that were enjoyed by many; they attracted locals and they beautified their surroundings, and they encouraged pilgrimages and stimulated income if you could become particularly distinguished and attractive, based on the beauty lent by your artisans and artists.
And a big church could employ lots of them, and thereby stimulate the economy. It seems that the Baroque Era and churches crammed to the rafters with art, may be an artifact of a very good job market for those architects, craftsmen and artists!
Yeah... you could copy some sheet music and share it around, but it still required skilled musicians to perform, play and sing it. And nobody was taking photos or uploading JPEGs of your art and sculpture, so it was fairly locked-in that people needed to visit, and see it in context. So it stood to reason that you could probably reconstruct Noah's Ark from the fragments of True Cross that were circulating around Europe... and how many fingers did your favorite saint really have?
Copyright-free church economics have sort of fallen apart since then. However, museums, arena concerts, theaters and the rest, they have all taken pages from the Church playbooks. The fact that a church can still draw in hundreds for a show with great production values, every week or daily, seems dull and unremarkable now, but a good rock concert or museum collection can evoke the same "goin' to church" fervor in people who like that kind of stuff.