Learn packaging and start creating whatever package you feel is missing from the repo, use distrobox (that's already in the repo, sudo eopkg it distrobox to get it) to add a distribution that packages whatever you need and then install it there, use flatpak (yes, because "I won't use it" without any further explanation is pointless) or appimage.
Keep in mind that if something (like Chrome, for example) is not in the official repo there's usually a fairly good reason for its absence, either technical (you can't build that package on Solus due to incompatible dependencies for example) or legal (you can't distribute the package that you created using Solus tooling), so requesting to add the "missing" package will probably not work.
