Yes, vulkan-radeon and the 32-bit equivalent of it, lib32-vulkan-radeon, provide Vulkan API support. They should definitely be installed if you plan on doing any gaming. I believe Steam depends on vulkan-driver and lib32-vulkan-driver, which vulkan-radeon and lib32-vulkan-radeon provide respectively. There's also amdvlk which also provides vulkan-driver and is AMD's proprietary Vulkan implementation. The general advice is to use vulkan-radeon though for the open source RADV implementation, although some games have been known to work better with AMDVLK.

If I were you though, I'd just wait until some package you install requires them. The fact that they weren't already installed just means you weren't using any Vulkan applications to begin with. The only caveat to this statement is if you're installing a game manually or via something like Flatpak, in which case it may be useful to install ahead of time. Up to you.

Another thing you might consider is installing the libraries necessary for compute. You aren't going to be doing many compute tasks on that underpowered 5700G APU, but when you do get your desktop GPU, you may want to install either ROCm, AMD's open-source compute stack that provides things like HIP and their slightly buggy open-source OpenCL implementation, or opencl-amd, which is their tried and true, proprietary OpenCL implementation.