I mean Pewdiepie still mostly just makes dumb videos of him and gets an absurd number of views, and has over 100m subscribers.
He stuck to his usual content and his margins just keep increasing since there's no added costs for a higher viewerbase.
Having a career.
It's very rare for someone to last decades as a performer in the entertainment industry, and online content moves faster than most. You don't want to suddenly have no audience age 35 with zero skills or experience outside making potentially niche YouTube videos.