I’m no layout expert, but I did do some desktop publishing about 15 years ago 10 min in Scribus had me tearing my hair out. Installed InDesign and, while it’s still not easy to catch up on the modern capabilities, it’s not there yet.

GIMP is just fine for casuals. It’s not close for professionals.

Truthfully I think that one major issue with open source programs that don’t have corporate involvement is that people who are great at code don’t always have the same skill in UI/UX. However, with support and a larger community, great things can happen. The barrier is getting that adoption level. If more people casually use the product and contribute financially or in code, it will help tremendously.