No one (except for Larian) is arguing that you have to roll a specific sneak attack. Just that you have the option to apply the sneak attack damage on a normal attack if the conditions are met.
Sneak Attack
Once per turn, you can deal an extra 1d6 damage to one creature you hit with an Attack if you have advantage on the Attack roll.
And the best way of doing this is to set a toggle, so that the sneak attack procs on the first applicable instance automatically, but you can turn the toggle off if you don't want to waste sneak attack on a low-hp enemy.
Similar to how, e.g. for Great Weapon Master: "On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you
can make one melee weapon attack as a bonus action." You don't have to make this bonus melee attack, but you have the option.
Or Monks: "When you use the Attack action with an Unarmed Strike or a monk weapon on Your Turn, you
can make one Unarmed Strike as a Bonus Action." Again, they don't have to make this unarmed strike. They can use their Bonus Action for something else instead.
Edit: And the link Rag put, but to be fair Jeremy Crawford's tweets aren't necessarily official rules, even if they are taken as gospel by many.
