Is it still possible for one person to design and develop a complete game with all audio/visual/game mechanics aspects in place (complete package). I have some interest in game development, but don’t want to hire anyone... but wondering if it’s even feasible anymore to go solo.
Short answer: Yes.
Long answer: It depends on the scope of your game. It's entirely possible for one person to create a decent game, but if you want it to be profitable, you will have to wear a lot of hats: designer, programmer, artist, audio engineer, marketing exec, and tester. Not only that, you will have to plan and manage your own project.
You also have to consider the timescales involved. Every feature will require new code, testing, potentially new assets, and will need to be designed in such a way as to be maintainable. All this takes time, so you have to decide how much time you have to devote to your project.
So to summarise:
You can totally do games as a solo developer, but don't expect to be able to produce a AAA game any time soon. Hobby/web games are totally doable within reasonable timescales and cost.
It depends on the scale of your game. Monsters like "Call of Duty" require thousands of person-years. You don't have that long. OTOH, if you start with the right tools (which you already know how to use), a new game can be done in day (if it's simple enough).
You should also consider your actual goal. If making the game is an end in itself, it's a very different thing than if you want thousands of happy users.