Is one who opens a YouTube channel for video games free of Haram [unlawful things] sinful if it causes people to waste their time watching the clips?

There is no sin in opening a channel for permissible games free of prohibitions. However, it is better to strive to benefit people. Electronic games are a distraction, and one should not waste time and effort creating channels for them, nor should one help young people waste their time on them. If one insists on opening a channel, then it should feature games that develop thinking or teach something useful, and it should be accompanied by advice and guidance.