Just some notes in case no one has mentioned them.
Can low level magic be taught at a school? If so, what kinds? Can the Elemental Evil cantrips be learnt in a guild apprenticeship? If so, irrigation on a large scale is no longer labor intensive, nor is changing the landscape to better serve the needs of building.
Are there people who can cast detect poison and disease? If so, is medical science advanced by an early knowledge of viral and bacterial science? Just accurately diagnosing diseases creates an unimaginable difference in general public health.
Comprehend Language and a ton of other rituals of low level totally change the ability of the learned to share and improve their knowledge. Look at medieval Baghdad. There were Muslim, Christian, Jewish, and “doubter” scholars just sharing knowledge and challenging each other and reviewing eachother’s work all day every day. Imagine if that was the norm for much of history.
Do magic and tech compete? This is a fundamental question. Do the Fey and the gods and giants and such shun tech, delight in it, or is it as much a mix as it is for humans? Can tech be mixed with magic?
In my own rpg Quest for Chevar, they mix fine, but magic swords are “better” than magic guns because most magic needs a connection to a creature with a conscious Will to operate, and so enchanting bullets is hard while enchanting Melee weapons easy, and enchanting the gun is limited. But in the future era, there are magi-tech warp stations, and spaceships all have magical and tech components seamlessly integrated. Rangers (the PCs) often have enchanted cars and computers even in the modern era.
Are there Artificers? This is related to the preceding question. Are there people who specialize in magical tech to the point they can make homunculus, iron defenders, walking turrets, enhanced magical firearms, etc?
Is the Keen Mind feat a thing that npcs can have? This has a huge impact on how information works. On how reliable oral traditions can be. On how like fiction the geniuses are.
Are Druids uniformly anti-civilization, or more like eberron’s, where some hate cities and some sell goodberry wine to rich people and teach farmers low level Druidic rituals To help their harvests be reliable and keep wolves away without killing them?
this will help determine population density, but also how many people need to be farmers, as well as what sort of social (and thus political) leverage Druids have in the world, and thus how “sustainable”/green industrialization is. Best answered per region/nation, tbh.
Does magic make the industrialized world less terrible to live in for the average person? Does magic trap smoke and soot from factories and refineries and the like, and maybe convert it into useful stuff? Maybe industrial byproducts end up replacing classic spell components, or lead to variant versions of classic spells? Imagine a fireball that does a bit less damage but obscures the area by leaving it covered in a dense black cloud of greasy smoke.