In Minecraft, there are so many weapons, but which one is the strongest without any mods?
Bow. Base damage at full charge is 9, or with critical hit, 10. Enchanted with Power V (+150% damage) it will deal 23 damage on full charge and 25 with critical hit. Additionally, Flame enchantment will add 4 damage (distributing it over next 5 seconds), and if it's still not enough, you can used tipped arrows of Harming II for additional 12 points of damage, so the maximul total is a whooping 41 points of damage for a single critical hit with a fully enchanted bow with a tipped arrow of harming - or in regular game scenarios, any proper hit (non-critical) with a regular arrow from a fully enchanted, fully charged bow - 27 points, which is enough to kill most regular mobs with one hit.
Netherite axe deals 10 base damage (15 crit), and enchanted with Sharpness V, 13 points. A critical hit with enchanted axe will deal 18 points of damage. The situation is significantly better with Smite V enchantment, 22.5 damage against undead, or 33.75 when dealing critical damage (hitting while falling down, e.g. after jumping). Still, against non-undead mobs it will be the same 10/15 points, so a dedicated axe against the Wither may be a good idea, but as general weapon it's rather so-so.
A netherite sword with Sharpness V and Fire Aspect II will produce a total of 18 points on a regular hit or 22 points of damage on critical hit. 27.5 or 37.75 with Smite V and Fire Aspect II against undeads, providing all the fire damage 'goes in'.
Then there's the matter of Sweeping Edge. It's a sword enchantment, which deals damage to all mobs within certain range of the one hit directly, and so the sword can deal thousands of points of damage per hit - distributed over a large number of mobs crammed into a small cell with vines protecting them from death from entity cramming.