Comment by ece

If you've used source based distros, you've noticed certain problems over the years. Upgrading compilers or runtimes can bring up problems that need to be fixed (maybe by recompilation or dev work). Upgrading libraries with circular dependencies is more painful.

After a while, you just want things to be more modular, have well behaved dependencies and release practices that just work to isolate any failures. Overall, Gentoo has done very well improving in this regard.

Chrome and Android are large enough projects with enough resources that they can brute force through these issues which is harder for a small distro to do.