Hi Quizzical,
The grade is a technical grade and has no relation to it’s safety other than the fact that more difficult grades are more difficult to do and people are more likely to fall off. The level of safety is easily included in the route description, ie Climb XYZ, grade 15 minimal protection, loose rock and water seepage, as opposed to Climb ABC grade 15, bolts every metre and a half.
Both 15s but vastly different experiences to climb.
Cheers,
Toc.
