This is going to sound weird, but I use Microsoft PowerPoint for almost all my general purpose graphics work. I create Amazon Kindle eBook covers, Udemy course card images, slides and a lot more with familiar and easy-to-use PowerPoint. If it's a heavy-lifting graphics project, I employ GIMP or Photoshop. If you're talking about drawing programs, I prefer Procreate and Clip Studio Paint. I recommend you keep it simple for the bulk of your graphic needs.
Hope this helps,
---Brian
