The Controller Series provided tangible gains and a lot of hope for mech pilots who never managed to break through in the past.
Perhaps they lacked talent.
Perhaps they were not courageous enough.
Perhaps they did not have a greater cause worth sacrificing their lives.
Whatever the case, the amount of mech pilots who remained mundane had remained huge ever since their profession came into existence.
Part of the reason why expert pilots, ace pilots and god pilots were so revered was because only a fraction of mech pilots succeeded in attaining one or multiple breakthroughs.
This thoroughly mythologized the heroes that managed to succeed against all odds, but also left a huge amount of regular mech pilots behind.