these are the exact same fucking characters from holyland, is this mangaka just incompetent as fuck?
Slightly different looks but I think he was going for a more evolved (not better) style compared to Holyland. They certainly act the same though. I have not read Jisatsutou but I assume the MC is the same beta shut-in type going by the synopsis. Many mangaka are one trick ponies and use the "same" MC consistently.
On the art front: you are reading something where the art is supposed to be realistic, most manga characters look the same if one removes their wacky unique traits such as Raybands, a scar, or drillhair. Some call this "sameface". Unless it is being drawn by a genius you will see sameface frequently. S, this is a case of OP having to read more manga.