Related: The Octavo systems system-on-package: https://octavosystems.com/
It's a TI AMxx series linux computer in a package on package module like a raspberry PI is.
It comes in two variants, a regular pitch BGA and an ultra wide BGA so that it is actually possible to hand solder it! (or with hot air or a toaster.)
It is what is used on the Pocket Beagle.
It saves you the need to to most high speed signals and really the hard parts of building a higher-performance board.