I realized what it was because of the reply comment but I clicked it anyways because I am on Mozilla Firefox and by default YouTube videos don't autoplay.
iirc Google Chrome has some bizzare byzantine(?) rule engine that determines whether a website is allowed to autoplay and I suspect (with no evidence) that the rules are set up so YouTube can autoplay videos without prompting the user.
iirc Google Chrome has some bizzare byzantine(?) rule engine that determines whether a website is allowed to autoplay and I suspect (with no evidence) that the rules are set up so YouTube can autoplay videos without prompting the user.