In a recent interview with IGN, Neil Druckmann of Naughty Dog explained how the opening to The Last Of Us Part 2 was originally envisioned. In the final release, players work their way through a small portion of Jackson, a safe haven where Tommy, Joel, and Ellie have been living. Here, Ellie goes out on patrol, and the game quickly moves on to the inciting incident. However, the original idea for Jackson was to make it a small open world area for players to explore at their leisure.
The game already has one large open world section, right at the start. As Ellie and Dina enter Seattle, they explore this portion of Seattle and uncover a lot of secrets, as long as you as the player find all the clues to piece stuff together. Jackson would have been just as open, though I doubt it would have had any secrets to uncover. It may have had some small arbitrary quests to go on for people you come across though.
The plan was that Abby would be introduced as a new settler in Jackson during this opening sequence. Depending on how long it took players to wander around as Ellie, taking in all there is to see, the way that Abby was introduced to the story would be different. However, all of this uncertainty created a lot of open ended entrances for Abby, and in the end I think it proved to be too ambitious for Naughty Dog to pull off.
There’s also the fact that Abby killing Joel is the reason for the meat of the game. If the game took much longer to get going, it may have felt totally different to play. I’m not saying that it would be bad, it just might not appeal to as many people.
The key to a good game is getting players invested in the motivations of the protagonist, and getting them moving around as the protagonist, as quickly as possible. In the original form, The Last Of Us Part 2 just would have taken too long to get into. As it is now, it still takes a while, but it’s a fun ride all the way through.