Between the half-orc’s Savage Attacks trait and the Elven Accuracy racial feat, which is better?

The description of the half-orc’s Savage Attacks trait says:

When you score a critical hit with a melee weapon attack, you can roll one of the weapon’s damage dice one additional time and add it to the extra damage of the critical hit.

The Elven Accuracy racial feat for elves and half-elves grants the following benefits (XGtE, p. 74):

  • Increase your Dexterity, Intelligence, Wisdom, or Charisma score by 1, to a maximum of 20.

  • Whenever you have advantage on an attack roll using Dexterity, Intelligence, Wisdom, or Charisma, you can reroll one of the dice once.

Generally or mathematically speaking, which one of these is better?

If you need a context, let’s say Fighter/Champion level 3 (critical on 19-20) and Fighter/Champion level 15 (critical on 18-20). Or let’s say Fighter/Champion 15 and Warlock 5 with Hex on the target (extra 1d6 per hit, which would be rolled twice on a critical hit). Or any other similar effect which adds dice rolls on hit which would then be rolled twice on a critical. Let’s say we’re using a 2-handed weapon that does 1d12 damage.

Let’s also throw in the Great Weapon Fighting fighting style (Fighter 2):

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

From my (basic) understanding, the Elven Accuracy feat would provide a lot more critical hits.

GWF and Savage Attack push the average damage up, but I’m not quite sure how to calculate the two scenarios.

I would really enjoy an analysis similar to what was provided here: Does the Resilient (Con) feat or the War Caster feat most improve the chances of maintaining concentration?