The context:

I've never went to school for photography or videography but I had a passion and did A LOT of self study. Of course you bump on a lot of mistakes along the way but I ended up being the one man army of motion design, video editing, photography and videography (etc...) in a mid size company. My old design lead had more trust in me than this new one and now he's giving me very much second doubts about my skills. I came to this company a year ago so all this stuff was already bought, pretty neat stuff (we have a studio with lots of gear). But our camera is the sony a7siii, someone probably chose this one because video was a little more important in the marketing side. Now fast forward today, we make photos during/inbetween video shoots that might or might now be printed on (big) billboards. I already said this isn't the camera for print photography but I'm pretty sure he doesn't really believe me and thinks I don't understand the material. He keeps on persisting I should get some lessons in studio photography and more technical stuff, so my confidence has dropped in my skills, especially in the photo side of it. 



This is an example **screenshot** (being a screenshot might decrease the quality), shot with:  
ISO 800  
f5.0  
1/80s  
70mm (24-70 sigma lens)  
200% zoomed in on the first picture  
100% on the second one



I was pretty sure that this noise (especially in the background and shadows) was pretty unavoidable, with this camera, for photography. But now I'd like to hear you guys opinion, shall I get a mentor? 



PS don't question the weird object

Need help/advice regarding photo noise.