A fully customizable protagonist for a mainline GTA game would be incredible, especially if it happened in GTA 6.
Customizable protagonists are nothing new in the GTA series. Players can customize Carl Johnson's looks in GTA San Andreas, but a fully customizable protagonist didn't happen until GTA Online.
Of course, it should be noted that GTA Online is a part of GTA 5. It's strictly an online game, different from having a fully customizable protagonist in the base game.
Should GTA 6 feature a fully customizable protagonist?
The question of 'will GTA 6 have a particular feature' is different from asking 'should GTA 6 have it.'
There is no way to know the answer to the former question, but the latter is a yes for some parts of the playerbase. Fully customizable protagonists are commonplace in video games, particularly in RPGs.
Fully customizable means that the player can choose the gender, skin color, body shape, and random clothing apparel for their protagonist. It doesn't necessarily mean that the player can choose their own story.
While that is a nice feature, it isn't an obligation in most games to implement a fully customizable protagonist.
GTA 6 and the unknown
Even if next to nothing is known about GTA 6 presently, it is doubtful that a fully customizable protagonist would kill the game. In a game like Saints Row 3, the protagonist is given a few voice presets to choose from.
If GTA 6 implemented something similar, then the protagonist wouldn't have to be silent like GTA Online. A fully customizable protagonist can still do anything a GTA protagonist is normally capable of doing.
Missions, side activities, and other characters can still be present with a fully customizable protagonist. Some minor activities like dating would require more effort if either feature were implemented into the game.
Still, it wouldn't be difficult to do what the Fallout games do (not lock choices based on the protagonist's gender).
Benefits of a fully customizable protagonist
The most apparent benefit to having a fully customizable protagonist in GTA 6 would be that players can more easily relate to them. While past GTA protagonists were awesome, they weren't always relatable to some demographics. Compare that to GTA Online, and one can easily notice how much easier it is to like the design of a particular protagonist.
A second major benefit of GTA 6 would be that players could spend a lot more time being creative with their creations.
They can opt to play as a meme character, or they could spend a lot more time on perfecting a more serious design. This would mainly apply at the start of the game, but it would still be significant.
Finally, it could be incorporated into more complicated gameplay. There could be certain dialogue if players created something specific, similar to how fat CJ was treated differently compared to regular CJ.
Rockstar Games could even go the extra mile in GTA 6 and make multiple customizable protagonists.
Why there should be a fully customizable protagonist in GTA 6
As mentioned previously, having the ability to make a fully customizable protagonist is a blast. There's always so much to do, and allowing players to be creative is never a bad thing.
It's a diverse feature that can be incorporated in several ways, so there are honestly a few dozen ways to approach it.
A fully customizable protagonist isn't a band-aid that fixes all problems.
While there are numerous advantages to having one in a video game, there are also noteworthy disadvantages worth discussing. Mostly, it's a lot more effort for the design team to try and create a fully customizable protagonist that isn't just a silent protagonist.
Another disadvantage is that it takes away the protagonist's iconicness when they don't have a set design.
Carl Johnson's looks are customizable, but players can easily remember him in his default clothing. If the GTA 6 protagonist were fully customizable, it would make marketing a specific design a little inconvenient.
If GTA 6 can't implement a fully customizable protagonist with some of the features above, then perhaps they should do so for GTA 6 Online. It would be a small step, but it would still be a step forward nonetheless.
Alternatively, having one fully customizable character out of multiple protagonists would be pretty nifty.