Are all of the high end weapons and armor crafted through smithing also found throughout the game once you level high enough or are there certain weapon and armor sets, or pieces, that can only be acquired through smithing?

Items are leveled, and even then, it will be rare to see Daedric. Even more rare to see Dragonbone.

To have better access to those kinds, it would just be better to craft them.

you can find glass, Nordic carved, stalhrim and daedric weapons when your level is high enough. Dragonbone weapons are found in the soul cairn at a high level.

There are certain weapons and armor found throughout the game that are not duplicable such as the Blade of Woe, Dawnbreaker, SpellBreaker, Ebony Mail, Miraak's sword, Azhidal's boots of waterwalking etc, etc. However for those common sets that can be unenchanted, through high level smithing and enchanting the character can make high end weapons and armor to which these only pale in comparison in effectiveness. So the waterwalking boots and Deathbrand set as examples are unique and unduplicable although they can be improved.

Legendary Dragons typically have Daedric armors pieces and weapons in their inventory. Also as Michael suggested the Soul Carin is a good source for Dragonbone weapons.