Yeah that'd be the straightforward answer, but after Wano he revealed his dream to the crew and the reactions were far too extreme for it to be the thing he's been announcing from day 1
Post Wano he tells the crew his "true dream" that he told Ace and Sabo when they were kids. We don't see what he says but the crew reacts in shock: here's the panel
To me it just makes sense thematically. The warrior of liberation, the freest man in the world would want to unite the whole world and have a huge party. And given everything that would require (uniting the world, getting rid of the World Government as it exists now, helping the various races and tribes get over their grievances and oppression), it tracks for me.
I think it's something totally crazy which seems impossible.
Read once a theory where his dream is destroying the grand line, which would connect the 4 seas.
It played well with the dreams of the other crew members. For example creating the all blue for Sanji.
But in the end it will something else which was probably foreshadowing since chapter one or so haha.
It's something a child would dream of ( he had it since he was like 4). And knowing Luffy something not very articulate. The big party or something like that is the most credible I heard but it wouldn't explain why some of the crew were startled when they first heard it, but that may just be Oda trying to mistify it.
Maybe it's that everyone's dream will become reality (which is also how the Devil's Fruit were born).
I think it would something so big and so small at the same time it's ridiculous.
Man, I love One Piece ahahah