I have used this resource for years. They have a large, easily searchable catalog. I have never failed to find something I can use for a background, overlay, texture etc.
With a free membership you get a much larger download limit. I find that I have never bumped my limit. Of course, with paid membership one gets an amazing download limit.
Can you imagine what would be if you joined illustrator and Photoshop or Inkscape and GIMP in one program? Those are professional programs that offer a multitude of tools and options to cover almost all use cases. Joining them would make the software extremely more complex, more prone to bugs, harder to develop and maintain and eventually more slower than they are actually, not to mention much harder to learn.
Affinity uses the same file format for all of its apps, letting you open any file in any program. Personally I believe this is the best compromise you can get without bloating the software with all possible functions that you probably may only need a fraction of the time. Keeping the apps focused will also help to expand their scope/functionality for the purpose they were designed for.
S0N0X reacted to Tsetsoh in Free CG Textures