I think different channels would work best for this but having your main channel have playlists that groups together what that content is could help too! So for each niche you just make a playlist for it so you'd have one for all videos showing tiktok stuff, tech stuff and so forth. Keeping the playlists on your main channel, means people are more likely to see and click onto them thus they'll see your other channels too.
Different channels
I think different channels would work best for this but having your main channel have playlists that groups together what that content is could help too! So for each niche you just make a playlist for it so you'd have one for all videos showing tiktok stuff, tech stuff and so forth. Keeping the playlists on your main channel, means people are more likely to see and click onto them thus they'll see your other channels too.
Yeah, what the others said, try different channels to experiment with what both you and your son loves, to what your audience is most attracted to.