is gaming as a whole too broad?
Short answer: Yes.
For one there is A LOT of competition among gaming channels, just because of the sheer numbers of them and with all of them doing such similar things. You should establish what you want to share with your audience. Do you make tutorials, share tips, show first impressions of games, have generic play through with or without commentary, do you do speed runs?
It would help to establish an audience if you stick with one game, but this can be very restrictive. Just ask
@GameVestment about it. However, even if you want to play multiple games, it's better to do one genre: platformers, first person shooter, mystery games, puzzle games, nintendo games, xbox exclusives, etc, etc.
You might be wondering why you have to choose when there is so much you like and the answer is simple: Your audience won't like everything. I really don't like FPS games, but love watching platformers. I watch tutorials for games I don't even play, because I find them more interesting and engaging then play throughs of that same game. Your audience needs to know what to expect from you. If you post a Apex tutorial one day, people will subscribe hoping for more of that specific game or type of content. But if you then do a Ace Attorney playthrough, these viewers will be disappointed and unsubscribe again. And vice versa, obviously.
You need to be consistent in your content to be of value for your audience. At least pick a type of game/genre you stick to and ideally also figure out what your video has to offer as value: entertainment, education, immersive play, etc. If you just want to play and upload whatever you want, that's also fine. But just know that it will be much harder to build an audience and the whole reason for sharing your gameplay is for people to see it.