No, you can grant yourself this inside an unprivileged user namespace. `unshare -Ur capsh --print` lists the capabilities inside a user namespace and demonstrates that it has both CAP_SYS_ADMIN and CAP_NET_ADMIN.
Almost all distros allow unprivileged user namespaces, and in my opinion this is the right decision, because they're important for browser sandboxing which I think is more important than LPEs.
I don't think namepsace CAP_SYS_ADMIM grants you access to write non namespaces sysctls like modprobe_path