An archer doesn’t get close to the target consistently through luck. If their arrow flies and strikes the bullseye they have been fortunate: this particular moment of skill has been rewarded.
It takes time, effort and learning to build capability to the point where someone can consistently hit their target. An archer has a different skillset from a researcher, but both need to demonstrate a great level of commitment and growth tif they are to be good enough to meet the challenges that face them.
When you sit with your examiners, discuss your work and respond to challenging questions you will show yourself to be capable of hitting your target consistently. There’s no luck: it takes time, effort and learning, everything you will have invested in during your PhD journey.