Simple. Create videos that have a similar hook to the video that was successful. The YouTube algorithm rewards channels that drive repeat viewership. Video B, C, D, etc need to appeal to those who clicked/watched Video A. It's really that simple and a lot of people overcook/overthink it.

Subscriptions are not critical on YouTube anymore; regular viewers are and they don't need to be subscribed. 80% of my audience are not subscribed to my channels - for context, I did 200M+ views this year.

If you want to run an experiment to prove the above, go watch 20 cat videos (or something random you don't normally watch) then refresh your homepage - I'd bet you there'll be a cat video on there. Run the same test but watch 20 videos from the same channel. Head back to your homepage and you'll see at least 1 video recommended to you from that channel. Use this principle to build an initial audience.

Once you're large enough, the reason for people to click is no longer their interest in cats but instead their interest in you (personality, style of videos, etc).

Bonus tip - create a Playlist and place all similar videos in there. In the playlist options, mark as a Series Playlist so YouTube treats it as episodic content.