It's desirable to have some kind of simple base to start from that is an easy-to-configure platform to deploy any kind of metabolic machinery.

Their "minimal" cell is not quite a minimum product because it depends on prebuilt ribosomes and can't reproduce on it's own. No danger of gray goo!

This is more like it

https://www.jcvi.org/research/first-minimal-synthetic-bacter...

but those guys could probably add components to their cell to make it truly self-supporting although in biology there is a big difference between "barely works" and "high performance"