First things first: Overmelding, or even Pentamelding is only worth it on gear that will stay with you for a while. So, any endgame-gear, may it gathering, crafting or battle classes.

For Crafting its pretty much absolutly worth it to outright required - this is assuming that the crafted gear is shared by all classes (always the case for belt and right side, so those should always be stuffed with materia). You'll need to hit certain stat-caps, either outright given by the game (or you wont be able to craft the item) or required to perform rotations or use macros to craft highend-stuff. Even though its a huge investment and takes time, you'll be all the more thankful for being able to hit a 2-button-macro to craft the new raid-food instead of having to deal with a lengthy rotation because you didnt bother to put in enough CP, craftmanship or control to be able to use said macros.

For Gathering its not really needed or at least not to that extend - there are obviously certain caps you need/want to hit here aswell, but you can often do that without extreme overmelding. Hitting 700 GP aswell as the needed stats to gather new items in HQ is very useful though!

For DoW/DoM: It depends. For a tank, crafted and melded accessories are BiS for example because non of the tomestone/raid-stuff has DH on them and because they have to put in that one strength-materia, that fills the one slot they'll get on the non-crafted stuff.
For any other class: It might only be worth it if the substats on a piece are really, really shitty. There are always items that have a higehr ilvl than the crafted gear, which means they have higher mainstats. Unless the substats are absolute garbage you dont wanna lose out on those points! However, this is in general only "semi-required" or of importance if you're doing the current Savage-raids. You can do any content in the game just fine without pentamelded gear (even Savage, really - but if your group is struggeling and needs to push DPS, every point might count...)

So, the two general keypoints/questions here are:
-Are you gonna use the gear for a long period of time (about 6 months+)?
-Do the added stats enable you to progress further in the game with more ease or are they maybe required to progress at all?

If you can answer both questions with "Yes", then pentamelding (or at least overmelding) is worth it.
Keep in mind though that the materia-melder-NPCs wont help you with that! You either need to do it yourself (requires crafting classes of a certain level) or have someone else do it for you (its easiest if you give them the gear and materia so they can just throw those glittery stones at the freaking piece of armor until one sticks, without having to go through an annoying menu all the time...).

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So much for a general answer...
I'll admit to have peaked at your Lodestone-Profile and unless Aldagrate is an alt-character and you've wanted this information for your main one, I'd say: Pentamelding isnt worth it for you. Crafting and Gathering is out due to the lack of respective classes at level 70. I'm no expert on dragoon, but afaik that class doesnt has any substat that would outweigh an increase in your mainstat. You also dont seem to raid? (Even though I'm struggeling a bit right now to figure out how you managed to upgrade that headpiece then... ooooh, hunts, probably?) And as I said: Unless you need it to push raid-progress, its not worth it.
One last thing I noticed: That one crafted piece that you're having there is a Normal Quality one - you never ever want to overmeld that. IF you overmeld, you overmeld High Quality (HQ) gear. Overmelding NQ is absolutly and under no circumstances worth it!

So for you, in your current situation, its probably not worth it - generally speaking the usefulness ranges from "pretty much required" (crafting) to "better do some of it" (gathering; tanks) to "eeeh, if the other stuff has really shitty substats, I might bother" (healers, maybe bards and BLMs for crit and spellspeed - huge maybe though, highly depending on the piece of gear)