If Grand Theft Auto 6 was a boat, it would've sunk already. The game's development is full of holes and leaks. Now, a new one has sprouted and it claims GTA 6 is further along in its development than expected.

Rockstar Games confirmed the next GTA game last year and most of us assumed it's still years away from coming out. The earlier footage leaks showed a rough build of GTA 6 as well, which seemingly confirms this. But, as it turns out, this isn't the case.
According to Rockstar Games insider, Tez2 (via GTA 6 News & Leaks 2.0), they've found multiple files alluding to a nearly complete build of GTA 6 already existing. Specifically, Tez2 claims that Rockstar is just polishing GTA 6 right now.
Of course, if this is true, the amount of time a game spends in the "polishing" phase varies greatly. In this day and age, it wouldn't surprise us if Rockstar spends the better part of the next two years trying to make GTA 6 the best game that it can be.
A more recent example of this is Final Fantasy 16. The game's producer, Naoki Yoshida, confirmed in May last year that the studio is already focusing on polishing FF16. But, nearly half a year later, it was revealed that FF16 would come out on June 22. If we follow the same timeline, GTA 6 could be out as early as next year. However, as GTA 6 is a much larger and a more expansive game, Rockstar might spend longer polishing it as we've already mentioned.
If nothing else, a two-year polishing phase starting from now would put GTA 6 on track to come out in 2025, which is in line with the most prevalent rumors.
Rockstar officially revealed Grand Theft Auto V in November 2011 before launching it two years later. The in-development GTA title could follow a similar timeline and be revealed later this year, presumably at this year's The Game Awards.
With that said, the main takeaway from this leak is that an official reveal/announcement, preferably with a trailer, is coming sooner rather than later.