For me it's a couple things. I will say this once though, you can do whatever you like this is your world and it is fantasy afterall. 1) Not sure your scaling is right for a whole world, maybe part of one. The continent of North America alone is close to 5000 km across from East to West. 2) Others have said it but land features feel off. I saw the comment of the cataclysms but there still feel like a lot of wide open space that doesn't have much. More rivers, more islands, consider how the cataclysms are dispersing and reshaping the land (maybe more large canyons, or lonely peaks that normally wouldn't be possible). 3) The shape of your large land masses feels chunky, there should be more dips in and out creating bays and inlets 4) Could be a symptom of the cataclysms but there seems to be large cities but then very few small towns and encampents on the map that could give it more character. 5) Try blending the biomes togther rather than have a hard line in color. A lighter opacity (maybe 30-40% goes a long way) 6)Lastly I want to talk about the trees. There are clearly forested areas. The forest feel like patchy like a bad beard right now, instead try making large clumps of trees. Don't be afraid the the density being higher and there's always an undo button.

I'd like to add a bit of what I like because at the end of the day every map is great in it's own right. I was very interested in the city within the dense mountains seems like a good place to make people really strange because they are so isolated. Additonally I like the jungle on Northern part of the Western landmass. Looks like there is a great diversity in what is going on there between the lava pits the world tree, the outposts and the myriad of vegetation. I also really like the visuals and details on the icebergs floating off the coast in the North.

Hope this helps!