Why don't preachers go around summoning demons any more?

not allowed to put god to the test, and you can't summon angels...

So go summon a demon! If a preacher legit summoned a demon that would be pretty convincing that there's an ANYTHING supernatural

....and some of the old Popes went around doing that all the time, like, for fun

it was deemed an inefficient subspec so in the name of efficiency they just blacklisted it. pretty utilitarian

Most priests today opt into the Zeal or Order Domains, and they don't get summoning spells.

All I care about is that priests can resurrect the dead and remove curses.