1.3-release will retire support of 32-bit multilib on x86-64bit arch.
As of December 2018, Valve's Steam client and many games continue to require 32-bit libraries.
In the short term, Steam on Funtoo Linux is best achieved via a 32-bit chroot. Steam (Gentoo Wiki).
This report is to request support of Steam client ebuilds on Funtoo once Valve updates the client to 64-bit only.
Note: game-util/steam-* ebuilds are currently sourced from external repositories.