Well, Games are one thing and Life or Death fights another. Chess is a great way to sharpen your mind, but I would not try it in splitseconds with my life on the line. Trained instincts on the contrary is something I would strife to acheve.
I totally get that, I only use words like "most" cause I think there are some exceptions to the rule. In my initial post, I did not mean a preset video-game type of combo, just using the word to mean pressing your attack instead of just stoping at a few swings. In theory, the perfect fighter will not just be stringing lots of moves together, either preset or random, but reading his opponent and then choosing the best possible move to do next, and will not be thinking just the next move ahead, but many moves ahead. But such a fighter would need the greatest skill, talent, and training. To get there you have to start somewhere, and a preset combo could get a rookie used to the idea. The true goal is to always choose the move you think best, but since nobody will realistically just jump in and be able to do that, they need to build up to it with more simple things.
As for video games, as I was implying, I do not think that playing them, or chess, or whatever else is going to make you better at fighting. I was saying that it can be a useful analogy to combos in real fightings. There are uncountable variables in a real fight, strategy games gets rid of all those and focuses only on reading and out-thinking your opponent. Agreed, of limited or no use in a fight, but still quite useful in studying the 'hows' and 'whys' that make combos successful.
A note on the combos looking more impressive. Yes they do, that's why you see people fight that way in movies. But the reason they are impressive is people find feats of skill impressive. You also see people use combos in basically every fighting art, especially among the most skilled. Boxing, fencing, martial arts, wrestling, etc. So that tells me two things. First is that it takes a lot of skill, second is that it is effective (the greatest fighters in the world wouldn't do it if it wasn't).
As for my sparing experience, nothing really as organized or practiced as this. I used to do some bare-knucked sparing with my cousin, wrestled with my brother while he was doing it in high school, and back when I was in high school I made some practice swords and went at it occationally with different people.