pawsplay
Legend
And rapiers literally were used in warfare. You’re conflating it being an officer’s or specialized unit weapon with the idea that it just wasn’t suitable for warfare, which is innacurate.
Anything is suitable for warfare, if you're desperate. Can you give me a single example of a rapier being used as the standard sidearm for any officer or "specialized unit?"
The fact that they were never a rank and file weapon is a matter of expense and required time to train, and the fact that any one-handed sword was steadily losing relevance as a regular soldier’s weapon by the height of the rapier’s popularity.
The US Marines stopped drilling with the saber about two decades ago. The modern tactical knife is functionally similar to a wakizashi or a gladius. It isn't pikes that have diminished the sidesword, it's helicopters and drones.