Now that you have an idea of what multilib is, it is time to decide whether to enable that support or not. Depending on the circumstance, it may be necessary.
Some don't not know this unless they push the limits of the games they play, but many games on Steam are 32-bit. Some games are no longer receiving updates while some are still being updated but are still 32-bit to this day.
Not only are a lot of games 32-bit, but Steam itself requires that
you have 32-bit libraries. If the 32-bit libraries aren't on the
system, Steam will quit, saying it needs a library such as
libc.so.6. You will need the ability
to execute 32-bit applications as well as all the libraries
necessary which is laid out in Chapter 3.
Wine can depend on certain things, differing upon the architecture being built. As these architectures require a more in-depth explanation and a roadmap on how to approach things, see Wine Dependencies which will help you better understand whether you need 32-bit libraries. If you need a given architecture and it says it needs 32-bit libraries, lib32, or MLFS, proceed to the next page. If you don't need those libraries but need the i686 MinGW-w64 toolchain, you won't need multilib for Wine.