The most disliked video on YouTube is Rewind 2018. According to the opinion forwarded by Agent Gray, YouTube has many ads and there's a anti-adblock to bypass YouTube. But in the post replied by Nyxia, there are many ppl claimed that YouTube premium subscription, ads everywhere.

The claim that YouTube Rewind 2018 is the most disliked video on YouTube is well-supported by multiple sources. It surpassed previous records for dislikes and has been widely criticized by the YouTube community for various reasons, including its content and representation of creators.theverge.comtheverge.comYouTube Rewind 2018 is officially the most disliked video on YouTubemashable.commashable.comYouTube Rewind 2018 is now the most disliked YouTube video of all timecnbc.comcnbc.comYouTube's 2018 recap becomes most disliked video ever posted on the siteen.wikipedia.orgen.wikipedia.orgList of most-disliked YouTube videosen.wikipedia.orgen.wikipedia.orgYouTube Rewind 2018: Everyone Controls Rewind

Regarding the opinions forwarded by Agent Gray about YouTube having many ads and anti-adblock measures, it is true that YouTube employs various strategies to limit ad-blocking software effectiveness. This is a common user complaint as ads are a significant part of YouTube's revenue model.

The post replied by Nyxia mentioning many people claiming that ads appear everywhere even with a YouTube Premium subscription reflects ongoing user frustrations. While YouTube Premium is designed to provide an ad-free experience, some users report encountering ads or promotional content within the platform, which can be perceived as intrusive.

Overall, the input combines factual information about the dislike status of Rewind 2018 with subjective user opinions about ads on YouTube. The factual part about Rewind 2018 is strongly supported; the ad-related claims reflect common user experiences but can vary depending on individual circumstances and changes in YouTube's policies over time.