I don't think there is nothing wrong with you I mean. I'm a fan of the old yu gi on anime series. I watched from season 1-3. The only one I watch now is yu gi oh arc v. Because that one really reminds me of the old school yu gi oh series. Anyways. The game I am sad to say I didn't play. But I would imagine the gameplay of being in the setting of how the anime is. If there is a yu gi oh game that you stopped playing because you got bored of it then that's fine. The newer games tend to bore you out because it has things in there that wouldn't really consider much fun. So in all honesty its better to keep on dueling in real life as you said that you enjoy that more. Play what you feel is fun for you.

At least you even got to 5D’s, I gave up before GX even started because to me, it just got so bad, so I haven’t seen more than 1 episode from each series after the original series. It’s not your fault, yugioh just lost its charm, they tried to do too much and change too many things, and it just didn’t work out. The same goes for many other shows as well, they just stop being interesting after a while.

There's nothing wrong with losing interest in a show / video game franchise. Things always change with time, and as they change, your level of interest and how invested you are in it will change as well. These things happen.

If anything, there'd be something wrong if you blindly followed a series or franchise regardless of what happened or how it changed. If you feel that way about something, then you might want to consider looking into if it's a problem or not. Even then, there are things of great quality worth following for the entire thing, they're just much more few and far between than the ones that shine brightly at first and burn out quickly after the gimmick starts to get a little tired out. 

I personally loved the original YuGiOh series. I watched it up until the point Yugi was no longer the main character. I absolutely hated the fact they tried to change the cast, and thought it was a huge mistake. Though I was much younger at the time, and can't see myself going back and still being able to enjoy it lol. I actually tried a while back to re-watch the Pegasus arc, and Joey's voice was just too much for me. It was hilarious hearing the way he would say "Flame Swordsman" and such, but it got old really quick

Maybe your tastes and preferences are simply evolving and you're interested in something else. I can tell you there is very little I liked when I was 8 that was the same when I was 12, that was the same when I was 18, that is the same what I like now.

Sure, there are some themes that are the same but games, shows, activities, and more, that I used to do, I just don't do them any more. They don't appeal to me and there's nothing wrong with that. I just like other stuff.

If you've gotten away from it and you don't like it any more, don't apologize. Just figure out what you're into now and don't look back. There's nothing wrong with moving on with anything.