If you want something more professional you can look to the Affinity products which have a very reasonable one time fee:

https://affinity.serif.com/en-us/

I personally like Affinity Designer and have designed quite a few things with it. They are behind illustrator on features, I can't deny that, but I've been able to find answers to everything I needed.

Also they have solid developers working on the app. Check out this technical explanation of performance improvements to their rendering pipleline:

https://www.youtube.com/watch?v=JnfxzknVK_0

For a photoshop replacement, however, I would say Krita hands down. Again, its not as polished as photoshop, but I prefer it over Photoshop at this point even with all its rough edges. I really need to make a video or something about how to set it up and use it correctly but I think its got a lot more going for it.

Krita is closer to a Photoshop competitor than Illustrator. Inkscape is like Illustrator but honestly it is not very good, mostly due to seriously poor performance.

I don't know if Atril is a good Acrobat Reader replacement either. Does it support PDF forms and annotation? That's what most PDF readers are missing.

Apple's preview is pretty great from that point of view. I've also used Xournal++ for that in the past.

I've been using Inkscape since it was SodiPodi. It's gotten better, but the interface is still too jumbled. Affinity is much nicer to work with.

I will say that if I really need the end result to be an SVG that I can modify in a text editor later, Inkscape is better for that.

Yep -- Inkscape might have some advantages in exporting SVG to FreeCAD, too -- I've seen some differences with Affinity Designer that I don't quite understand.

Or more likely I just don't understand FreeCAD.

For pdf reader and annotator, https://docmadeeasy.com is a good alternative.

Lately I've just been using Microsoft Edge for viewing and filling out PDFs. It has the handy ability to draw on and sign documents. That's about all I used Edge for.

<3 Krita