Neonchameleon
Legend
I don't think the rapier is bad; it was a tongue in cheek reply to a silly comment that was presented as absolute fact saying that one handed warriors should take the rapier. I don't think the rapier is bad. I said it was for amateurs, and I meant it but didn't mean that there were no amateur melee fighters in D&D. The rapier, as the best dex based melee weapon, is good for dex based combatants in melee. This is great for e.g. rogues, archer rangers, bladesingers, melee bards, and most other characters that can hang in melee but aren't primary melee folks. I'm tongue in cheek calling these characters amateurs.if you think the rapier is bad... what are your thoughts on the Longsword?
As for why to run a strength build over a dex build it's because if your primary combat role is melee damage strength builds have a significantly higher cap in most cases.
- 2 handed weapons are all strength based (which was accepted in the comment I was replying to).
- Barbarian rage only gives bonus damage to melee attacks made using strength.
- If you have the ability to get a combat feat then the highest damage one handed weapon is the staff or spear using the Polearm Master feat to allow you to attack as a bonus action and sometimes as a reaction. This, of course, only works with strength.
- This is especially easy for fighters (who get the free feat at level 6)
- It is also especially beneficial for for paladins (who get extra damage per attack for free at level 11 and also only need to hit to trigger smites).
- There's even a case for melee clerics to take Polearm master although it isn't nearly as compelling due to some great bonus action spells like Healing Word, Shield of Faith, and Spiritual Weapon and to often casting rather than attacking. But the extra 1-2 attacks when attacking plus the extra d8 damage per attack are nice.
The longsword? If you're playing a medium sized rather than small strength based character and 1lb of encumbrance doesn't matter then the longsword is strictly better than the rapier for you because you can use it two handed for more damage. If you're going sword and board it's better than a spear or staff (d8 vs d6) until you have Polearm Master. I therefore consider it a weapon for journeyman characters

There are also exceptions at the edges. For example Echo Knights routinely use their bonus actions to resummon their echo so don't benefit so much from polearm master. And it's not saying you can't use a rapier as a fighter - simply that the idea that you should and by default if you are going one handed is bad advice.