The ultra wide angle camera/lens is not designed to do flat field copy work. Just like I a screwdriver isn’t designed to pound nails.
Yes, you can place your camera close to an object and the camera will take a photo, if there is enough contrast in the subject where you’re focusing. What you’re doing is not a sharpness test. You’re taking photos that the camera was not designed for or optimized for. If you want to test sharpness, go outside, in daylight and take some normal photos. If those are blurry, you’ve got an issue. But from what I can see your camera is behaving normally, given your testing conditions and subjects.
Just so you don’t think I don’t have a clue I taught photography at MSU for 5 years, have a degree in optical engineering and have been involved in various forms of photography and videography on and off for 40+ years.