look at television
look at movies
look at award shows
look at celebrities
look at social media
look at mainstream news media
look at most of the internet news media which is actually high traffic
look at fiction and screenwriting
anime is mentioned one or two times a year and thats it. which has been the status quo for decades. and it is generally always mentioned in the context of being a fringe subculture. anime is still not mainstream. not in the united states at least. theres very small minority of anime content that its OK to admit you like or care about within the intelligentsia.
but it probably just begs a discussion of what constitutes mainstream any more. which is a question of how much do insular parts of the internet matter Versus how much do people still cling to old media. i still think the mainstream is firmly old media and not internet media. age is not a factor. i dont think younger people decide what constitutes mainstream. but its all just semantic hair splitting.