Precision: MacOS openGL is frozen a 3.3 on some Apple hardware we support. So this is the common denominator for now.
If the system does not meet the requirement, an error message will be displayed at the top of the viewport.
So until there is full Metal support, this will be the state of EEVEE Next on MacOS.
Apple is currently providing patches to have a fully working Metal backend. This should provide better performance than of a MoltenVK implementation in some areas.