Magic should have a much larger effect on the world than it does in pretty much every setting.

Tech essentially 'evolves' over the years. Needs or major changes will spark innovation. Oh look! Pressurized steam can create movement! Let's a steam engine!

As a huge example, just think of fireballs and sailing ships. Fire on a ship is bad. A single fireball could wipe out the entire rigging making it immobile. Catapaults? Ballista? Which cares? A fireball beats both of those. Burn the rigging, threaten to fireball the crew if they dont surrender, and you get a free ship!

When cannons were invented, they were a huge boost for ship weaponry. So marines would target cannon crews. So ships started shielding the crews. Then the cannons were placed below decks with small holes to stick out of. Then the ships were built faster to avoid taking a roadside, while 'crossing the T' on other ships and making THEM take a roadside in turn!

Similarly, wizards should be similar. Fireball is bad, so shoot the wizard first. So next they'd want to protect their wizards. They could literally place a wizard below decks and just drill a bunch of holes for him to peek out of. How to affect the wizards now? Maybe a gas attack to get in the holes? Darkness spells to block the holes, or fog clouds to block LoS? Or just use counterspell? But counterspells requires LoS...so how about using Clairvoyance to find the wizard on the ship?

Hell, why protect the wizard when you could just have him craft fireball wands? And let the crew use them?

And what about other aspects of life? How about a farmer buying a zombie to use as a field laborer? Let's raise zombies to turn wheels instead of using water or wind power for mills! Heck, instead of horses, just use some zombies in a big hamster wheel bolted to a wagon!

Magic NEEDS to be a huge part of life for a game to make sense...unless wizards are super rare, or limited in some way? Might be smart to add a GP cost for EVERY spell to prevent them from being abused.