When using ads the overall goal is optimizing for watch-time and engagements. That doesn't work well if you don't do proper targeting and extensive A/B testing within the ads system. Like don't target rap music to jazz fans type of thing.
If you get your campaigns at above average engagement ratios at scale then vids will have a high probability of appearing in extended suggested videos lists on similar channels over the long term along with search traffic.
The ad traffic itself won't rank the video, it's the resulting actions from the traffic that makes the difference.
A big caveat though is don't expect much from lower budgets, to push a video hard and fast with long term results using ads, it takes significant budget, not something that can really be done with a few hundred dollars.
