That statement made by @
Razamis is provably false. 4d6 drop the lowest is not just the first stat creation method, it's the default method with the other two specifically being optional rules. There can be no rational assumption that people are going to use optional rules, and it's stupid to balance the game around optional rules. If his statement were true, the array would be the default, and point buy and rolling would have been the optional methods.
Wrong.
The default is 4d6 drop lowest OR standard array, whichever you choose. The standard array is even the example chosen for "Building Bruenor: Step 3". Only the point buy system is the optional variant.
The average rolls from a player using 4d6 drop the lowest, will be roughly equal to the standard array. So the two official methods for generating characters more often then not gives you the standard array. The game is balanced on this assumption. This means that anything below the standard array is underpowered for what the content is fine tuned for, and anything above the standard array is overpowered for what the content is fine tuned for.
Rolling stats more often then not will not break the game, it will give you the standard array equivalent, in which case just use the standard array. The other options is that it will create an under-powered or over-powered character, and neither are desirable for most players. If you wanted to play a specifically under-powered or over-powered character, then why roll for it, just talk to your DM and adjust stats to make the character that makes sense for your RP idea.
Rolling for stats is simply a hold over from older versions of D&D when the game was newish and before game designers had learned from previous mistakes. That is not to say that they don't make mistakes today.
If you play a character that is above the standard array, or worse yet, if you have a party of players that are above the standard array, you are not getting the true experience the D&D5e designers intended when they balanced the monsters that you will be fighting. Everything will be less dangerous. There will be more work for the DM to adjust encounters upwards as the books suggestions will be off by however much your characters stats are off from the standard array.
Additionally most tables that I have played at that insisted on rolling for stats, usually had silly rules like "rerolls 1s once" or "reroll the entire set if there are not two or more 15s", which throws the average rolls off above the standard array.
The best choice is to use the standard array and experience encounters at their full strength, and make life easier on your DM. Rolling stats takes 30 seconds, and playing your character will require you to roll dice so often that not doing those first six rolls really should not be an issue for you for a better and more finely tuned experience.
