The ability to get advantage on saving throws to end the grappled condition does nothing at all. 

Why:

you make a saving throw to resist the grappled condotion - not covered. 

to end the grappled condition you make an athletics or acrobatics check - not covered.

This is clearly an oversight from the times when you made a save at the end of your turn to end the grappled condition instead of an ability check. 

The Goliath doesn’t have a trait called Powerful Build. What are you talking about?

If you’re talking about the 2024 rules that aren’t available on D&D Beyond to even the earliest early access tier for another month, well, no one here has the text for another month.

In the new PHB 2024 Grapple is now a Strength or Dexterity saving throw and not an ability check anymore.

There are previews out in the wild. 

It is a save to resist. An ability check to escape. As of the last UA and seemingly in the new book. Both are not covered by how the ability is written. 

I think the OP is related to this post on EN World:

While some (many?) of the issues on the list may be resolvable with sage advice, something that needs actual errata is the Goliath’s Powerful Build feature, which grants advantage on saving throws to end the grappled condition.

This officially does nothing, since you have to make an ability check to end a grapple. The saving throw is to avoid being grappled in the first place.

So Powerful Build will need to be rewritten so it either affects ability checks to end the grapple or saves to avoid being grappled (or both).

So, yes, it seems this feat needs a fix :(

Oh... it seems the fix was already done:

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It seems like there's been some errata incorporated for some of the new 2024 rules already!

Here's what I've seen so far (in no particular order):

• Goliath Powerful Build feature: originally applied to saving throws but now applies to ability checks.

[...] 

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