A lot of it has to do with multiple renditions of creative assets, such as @2x images. Because even if I add multiple code frameworks and libraries it usually doesn't amount to much. Creative assets typically take up the most space.
I will say one thing though - I do wonder if some of it is driven by multi-platform tools that are stuffing their own internals in there. Then you throw it all into one big package instead of splitting it up for different platforms. I've seen some internal app builder tools become quite large before. Especially by firms that think they need to roll their own version of everything, which AFAIK is standard operating procedure for a lot of those you mentioned.
I will say one thing though - I do wonder if some of it is driven by multi-platform tools that are stuffing their own internals in there. Then you throw it all into one big package instead of splitting it up for different platforms. I've seen some internal app builder tools become quite large before. Especially by firms that think they need to roll their own version of everything, which AFAIK is standard operating procedure for a lot of those you mentioned.