Small numbers add up.
A) 14 dex, +0 weapon, +0 arrows, +0 fighting style, level 7, against AC 18. Makes 20 attacks for 1d8+2 each; gets 1 crit, 7 other hits, deals 56.5 damage.
B) 20 dex, +1 weapon, +1 arrows, +2 fighting style, level 7, against AC 18. Makes 20 attacks for 1d8+7 each, gets 1 crit, 14 other hits, deals 178 damage.
+3 dex mod, 1 fighting style, 2 item upgrades; call this 6 "small number" boosts. Each granted a 20%ish boost, and compounded to 3x as effective.
The point isn't that 16 vs 14 makes you unplayable. The point is that 16 vs 14 at level 1 is the cheapest and easiest small number boost you'll get. And if you pick "naw I don't need it" when it is cheap and easy, you'll probably do it the next 5 times it is offered.
Because 20% isn't a huge gulf. But 1.2^6 is a huge gulf. And picking the 20% boost 6 times makes the PC in a different category than one who doesn't.
A) 14 dex, +0 weapon, +0 arrows, +0 fighting style, level 7, against AC 18. Makes 20 attacks for 1d8+2 each; gets 1 crit, 7 other hits, deals 56.5 damage.
B) 20 dex, +1 weapon, +1 arrows, +2 fighting style, level 7, against AC 18. Makes 20 attacks for 1d8+7 each, gets 1 crit, 14 other hits, deals 178 damage.
+3 dex mod, 1 fighting style, 2 item upgrades; call this 6 "small number" boosts. Each granted a 20%ish boost, and compounded to 3x as effective.
The point isn't that 16 vs 14 makes you unplayable. The point is that 16 vs 14 at level 1 is the cheapest and easiest small number boost you'll get. And if you pick "naw I don't need it" when it is cheap and easy, you'll probably do it the next 5 times it is offered.
Because 20% isn't a huge gulf. But 1.2^6 is a huge gulf. And picking the 20% boost 6 times makes the PC in a different category than one who doesn't.