This is a game that's always changing. The game of users vs algorithms. Youtube might decide to show your video in the recommended videos on the right side of other videos or it might not. In the end it depends on a lot of different points that get taken into account by the different Youtube algorithms. While a good video will get shared organically in a viral manner, the right-side recommendations play a huge role in the success of your video. The first point completely depends on your video quality. The second one depends more on what the algorithms find important. Let's explore and see what they find important and what you can do about it. Sometimes it is just experimenting by means of trial & error to see what works.
Downloading and re-uploading a video on Youtube won't get you ranked. In fact it might get your account punished for low quality videos.
It is surprisingly easy nowadays for their systems to rate a video just on quickly scanning the hash or content. Quality content is usually unique user-generated content at the least.
That does not mean that all user-generated content is quality. Just making sure the description and title are catchy is a pro.
Unfortunately things that do work aren't always fun. One of these is clickbait titles or pictures. You will come across deceptive titles or pictures on a daily basis on YouTube. You're thinking that the video will show you the latest farming technology because the thumbnail picture shows an amazing (non-existing) machine. The actual video will show otherwise. The title says one thing with a question mark. The video is the complete opposite. That is the sad reality, but it seems to have worked in the last decade at least. The algorithms don't care about that. They care about user retention.
The algorithms track exactly how each user interacts with a video. Youtube wants to keep an audience as long as possible on their platform. More minutes per user per day, means more advertisements shown, means more revenue. If you have a low quality video that doesn't incentivize the viewer to see as much of it as possible, it is a red flag for them. No interaction at all is another red flag. Naturally people ask for thumbs-up and subscriptions. That is not without reason, it helps the algorithm. This might become unimportant in the future though. In each video you will see popular Youtubers ask their subscribers to like the video. How annoying this does seem to the viewer, it still does help.
3. The final point is backlinks. A video that goes 'viral' on multiple platforms and get organic audience towards YouTube is liked by them for obvious reasons. You are bringing people, eyes and thus money to their platform. Backlinks on forums, social media where actual real people come though will give you a green flag with YouTube.