UE4 on Linux Must Be Improved

Please tell me - is UE4 on Linux on the same level like is on Windows? The same quality of graphics, the same tools available, etc. Compilation UE4 for Linux isn’t a problem for me. The problem is the cross-compilation. How can I build on Linux for other platforms than Linux itself? And having snap/flatpak the UE4 binary version on Linux can be easy done. One build for all distros? Is it really so difficult?