How hard is it to keep one brand associated with the one thing they do well? I'd understand it if you only have one brand your trying to expand, like Spotify starting to add video content. But when Google own a wide range of apps each with their own brand and identity, they really don't need to get everyone in one place like YouTube.
YouTube for me will always be about short video. When they stopped letting my buy movies on Google play, I didn't start using YouTube and just use Amazon now. When they stopped music, I didn't start to use YouTube music and stuck with Spotify. And now they are stopping Podcasts, I won't move to YouTube. I'm not that bothered but I don't see why they keep doing it, they must hemorrhage users every time and surely the value of YouTube with all these extra features etc is still less than the potential sum of the original parts.