Once you leave medieval, you open up the question of where it stops.
If people have firearms, do they have steam engines? If they do, do they have trains? If they do, do they have factories? Are we in the Victorian era now? If so, do we have lightbulbs in high-science areas? If you don't lay all that stuff out clearly, it makes it hard to PCs to get into the world and know how to engage with it.
I was in a game once, where the PCs heist was foiled by people using a telegram to tell the next town over what we had done. We had no idea such technology was even in the world. It was just one of the many things the GM had failed to mention. They saw their vision of the world clearly, but we couldn't.
Personally, I like lower tech, but that just does not work in seafaring campaign. We need galleons and cannons for that to fulfill the necessary fantasy. So if I am inland, it is medieval all the way. If on the coast or sea, early Age of Sail.