It's one thing to man-rate a *technology*; but the *production processes* and supply chain need to be equally robust. The Apollo Command Module was flown a half dozen times before any manned mission.
Apollo was a project that had economic scale. Many test objects were created and many beta units produced of critical components like the Command Module. While managing larger scale processes has its own challenges, the fact that the processes are *repeated* make them easier to debug.
The low pace of manned missions in the current era adds to their risk. You can man-rate the *technology*, but (a) it's minimally tested and (b) produced artisinally instead of industrially. There were, perhaps, 180 space suits of various types produced for Apollo (not all of which flew), which while below "industrial" production quantities was a lot of repeittion of the operations needed to make them. The astronauts on Artemis missions will be wearing suits produced at a rate of a handful over a decade.
While the hindsight and experience from sixty years of manned space flight reduce the technological risk, that is offset by the production quality risk from low cadence production. Assembly personnel and even vendors can turn over between production orders.