Ultimately, there are three reasons to craft:

1. Make gil by making items and selling to other players.
2. Save gil by making items for yourself instead of buying.
3. For the enjoyment of crafting, playing the markets, or feeling like an entrepreneur/small business owner.

The only equipment that you can make that is arguably superior to the higher ilvl items you can get as drops or with tomes are crafted jewelry overmelded with materia to have two primary stats (usually Vit + your class's primary). Since these are tradeable, this technically falls under reason #2.

As far as left side equipment, it isn't much better than comparable non-crafted and falls behind higher ilvl pieces. It takes a lot of time and work to be able to craft i110 and afford the materials. Crafting is ultimately not an efficient way to gear your left side in the grand scheme of things.