I am learning QuadSpinner Gaea. Though of course, most important maps will be in-world, but it doesn't hurt to have a realistic view of things too. I also think I can input my heightmaps into Blender to generate landscapes for my stories, both for narrative purposes since lands are literal constraints, and as art reference. One day it shall be done!

It doesn't look like much now, but there's so much potential here.

Here is the northern part of main continent in my world, in azimuthal projection from Gaea.

Also, this YouTube channel called Kilroy's Kartography makes these excellent tutorials on how to use Gaea, and he even has some free project files. Check him out! (video), Though I don't like the AI alternative he proposed, it does not even look good, Gaea has masks for rain shadow and all of those things, you can achieve a lot of realism procedurally generating it with right constraints and masking with your own handiwork than those algorithmic images.