I think one important thing about Rogue One's sacrifice was that it inspired the rest of the Rebel Alliance to unite and finally become a force to be reckoned with. Rogue One showed us that the Rebels were divided; you had Mon Mothma and Saw Gerrera's rebels both fighting a common enemy and each other, which happens in real life. One historic example of this is the Battle of Thermopylae where a group of 300 Spartans, reinforced by 7000 other Greeks, made a noble stand against 300,000 Persians. The battle was a crushing defeat for the Greeks, with all 300 Spartans killed and about half of the non-Spartan Greeks surviving and retreating (which wasn't an option for the Spartans as they'd rather die in battle than return in defeat). At least Rogue One managed to steal the Death Star plans! But in both cases, their sacrifice proved to be a significant morale boost which helped to unify their respective factions.