Ptolus is no more high magic than the PHB. In fact, it's designed to directly emulate the PHB and DMG in that regard. There are fewer omg uber NPCs in Ptolus than, say, Waterdeep, although both share the "metropolis with a big freaking dungeon underneath" space in the genre.
There is technology (guns, smoke bombs, cannons, hot air balloons, compasses, clocks), but it's a core part of the setting that knowledge of technology, including how to simply repair it and keep it operational, is slipping away as chaos rises and order recedes from the world. A group that dislikes technology in their D&D could make it something that only a handful of NPCs use and that PCs cannot buy. Conversely, it's not hard to increase its presence in the setting for groups that want more of it. (I like a little black powder in my fantasy, myself.)