People who says this manga is bad should probably read something else. This is called black comedy and it's actually a mild one at that. From the get go, as Kyle said, it's established as he is considered butt ugly by the world's standard and he gets beat up whenever he goes. Imagine getting transferred somewhere unwillingly only to be unwelcomed over there despite doing so much for the people. His mind is set to go home and play Sega rather than staying. Sure, he is OP but unlike other isekai mc, his life is painful and he wants to go home. Even before getting isekai'd it is heavily implied that he has no friends (because he plays Sega). You'd thought you would start over new in an isekai but turns out you just get beat up everyday, so what's the point? Better to just go home. Except it took him 17 years.
Also for people crying "Flags" y'all watching too much anime. For example, you probably have a teacher who's a huge dick saying you mean things, would you call that being a tsundere? No, he's just an ass. But we wouldn't know maybe that's not the case, maybe he's provoking you to get you to get your act together but when your mind is dead set to filter out the negativity, you don't think deeply about it, what is even tsundere. Moreso for ojisan, he wants to go home, screw these mean people. His vision tunnelled that he can't see the few people who actually nice or wanting to depend on him.
In a way, you can say his current position is his true happiness. Sure, he doesn't have isekai harem, but he has an understanding nephew who helps him to catch up with 17 year's worth of void when his other relatives shun him. While it's a recurring joke that he made wrong choices in the other world, people need to understand that this is a man who would rather go home and forget everything by playing games, but can't. At least he has the mind erasing spell but it's still not enough to compensate for missing out the things he like.
Black comedy is when you derive laughter from terrible things and if you can't accept this, you should read something else rather than demanding to shut it down. Also the art is fine. There is no need to be pretty as depression is the main joke here. Too pretty and it might seems like some misfired romcom with terribly dull mc. But he's not.