> But to me, despite all of this, there was a lot of sadness in that experience - because you know how desperately poor common folks were, how instead of building such status mega symbol they could have done some proper good.

Have you considered the idea that these could be considered jobs programs? It took a lot of masons, carpenters, ox/horse handlers, rope makers, quarrymen, etc, to run the supply chain for building this over the course of many, many decades. Just moving the obelisk to its current location took hundreds of men:

* https://en.wikipedia.org/wiki/Vatican_obelisk#History

Further, now, even centuries later, all of this architecture and art is helping the local with a fairly vibrant tourism industry.

Beauty, in addition to being a good in itself:

* https://en.wikipedia.org/wiki/Transcendentals

also has practical benefits.

> But not for church of that era, it was busy fighting for power and money of that world and trying to show how above everybody else they were.

The other option was to be rolled over by secular powers (princes, kings, emperors). If you think politics is nasty now, it was a (often literal) blood sport back in the day.