Requires many tenuous placements in a row and pieces need to be tested before weighting them. There should be solid placements within the pitch, but they are rather few and far between. During a fall, up to eight pieces of pro may rip out, but there generally is little serious danger. Takes several hours to complete a pitch. Most placements hold little less than body weight and falls are serious affairs.
Placements are often very marginal and pitches require many hours to complete.
No piece in the whole pitch can be trusted to hold a fall. No bolts or rivets in A5 pitches. A5 with poor belays that won't hold a fall. The leader pops and the whole team is airborne. No one sane has ever done this, and no one insane who tried came back to tell us about it.