Question on Rom Concept

[swallisa]

So not really knowing alot about rom structure and knowing just enough about linux to be dangerous I have a question for M1.

Since these roms are basically linux why can't the core / kernel be updated thru a package manager similar to say Fedora or such? Is it the size that the os would become running all the individual packages? Just seems with a kernel update when necessary and package updates when they improve would make for a more seamless experience that constantly flashing roms?

Excuse my ignorance!!!