I do not understand why mediawiki would need to think its success with criteria commercial businesses use with their customers.
Things like aiming to increase:
- User retention
- Search count
- Trust sentiment (as opposed to fact-based)
…sound like what a commercial business would target, not mediawiki projects like Wikipedia.
I imagine these criteria to be more important:
- accessibility
- stability (releasing the new stuff only when it's ready)
- technical simplicity