I don’t play dating games myself, but I don’t think it as sad as you say, because I don’t think it odd for people to have happy fantasies about their ideal partners. It’s totally normal. I think it’s the same as when I read novels, watch movies or read manga, it’s more fun if I find attractive guys in them as these things let me experience a different life and many times I’ve imagined myself to be the protagonist. Especially when I was a little girl, I’d often dreamed of marrying one of the attractive characters in stories.
This would be more akin to instead of wanting and looking for an actual real relationship or romance, only reading romances and blogging about them. In other words replacing the fictional for the real life experience completely. And depending on the situation, in some cases I can understand it without thinking it sad, but in many cases that kind of choice is sad because the person would rather have an unachievable sugar sweet fake fantasy than something real with a real person even if it never is anywhere as ideal.
I do agree that not living his actual life is unhealthy and sad, but I think he’s just playing games and blogging as a hobby, though.
This manga’s kind of confusing but the guy is not mistaking what happened in the game as something that happened in real life, but he’s actually meeting someone who is said to be a game character. So we’re confused but the guy’s confused too because that’s something impossible, but at the same time, he’s a bit convinced that he might actually be a game character because he looks a lot like the character.
So if he was kind of addicted to games and was not getting real life experience, meeting this guy irl and interacting with him might change him to live his own life?
Idk but I just don’t want to be prejudiced about people playing dating games, that they are replacing that for real relationship, because I’m sure most of them know it’s not real. It feels similar to some people saying ‘girls who read yaoi are all otaku who can’t date real men’ which is ridiculous. I know you don’t mean it that way, but idk.
You need to read the beginning again, where the MC describes exactly why he plays dating games and blogs about them. It is much more than just a hobby. In fact he states that he has no desire to date in RL, preferring the experience he gets from a dating game which he considers perfect.
I'm not going to equate a fictional character with anyone who plays a dating game. In fact, I think I made that very clear from start, that my comment wasn't about dating games as such, but about his not even wanting something real.

I found this both a bit odd and sad. Not that anyone playing a dating game is automatically sad, but if that is all that your life is, then something does seem sad. Also while the black haired character may have looked the same in and out of the game, he sure didn't act the same. And I would have thought the MC would notice. So aside from the story itself, I just found what was going on odd.