I've seen several people online talking about their grandiose plans for making a game better than Grand Theft Auto or something, and my advice to them is to sit down and
read aloud the entire ending credits for Grand Theft Auto or whatever game they think they're going to do so much better. Then remember each of those names probably represents at least a year of their time.
Even "indie" games typically take a dedicated team of several people a few years.
If you want to do a game by yourself, you either need a ton of skills or you need to be brutal about cutting the features. For example, a single person can build an interesting ASCII roguelike today. But you're not going to get an AAA look, that's for sure.