I will say, from personal experience, that personality is one of the most annoying ways to code the game. It makes for a much more interesting game, but you have to ask yourself if it’s worth it.
You’ll have to write a full different version of every scene based solely upon your character’s personality - if you’re doing it the way I’m assuming, anyway.
It can be confusing enough just to write flavor text, much less totally different scenes. Character will react to the MC differently, your MC will have different outlooks on things, etc. etc.
In a lot of ways, just using stats is far easier.
I’m, personally, guilty of creating stats screens with a lot of stats, but I also am writing/coding 3 games that have a trajectory of well over 900k words each (I may even split them up into shorter, more tolerable novels).
It all depends on how lofty your goals are. I think that it could turn out amazing, and I would love to see a game that truly feels different based upon your MC’s personality choices, but it’s going to be hard and stressful and possibly add months or even years to your overall writing period.
ETA: and I just realized I didn’t fully respond to your comment.
Mmm, I go in with a lot of world building. For my two Ilyaaren games (both of which are on hiatus on the forums but are well into production off-forum. Explosion is in testing with over 50k words playable, Citadel stands at 37k), I spent over 15 hours building the world and history of the world before I even realized that I wanted to write interactive fiction for it, rather than just a standalone novel or use it for a D&D campaign.
I’ve noticed, though, that it gets difficult to write with just a vague idea of what you’re going for. You need to have more than 3 major plot points in mind (for me, I always have the beginning, the climax, and the “real” ending in mind. Everything else is filler mush that I have to plow through to get to the scenes in my mind). For a long time, I tried to use online flow charts or Scrivener/Inklewriter (which has been discontinued) or Chronicler.
I’ve since found that a traditional outline, like I was taught in English class in middle school, is the best way.
EG:
I. Startup - introduce character
A. choose gender/name
B. interesting interaction with companion character
C. do you do the thing with side character or go off on your own?
1. do thing with side character.
a. it goes well (+ relationship)
b. it goes poorly (- relationship)
2. go off on my own
a. i get lost (-skill)
b. i find a magical artifact! (+ skill, gain artifact)
D. Important event that character goes through to get to chapter 2.
II. Chapter 2 - the story actually begins
Etc. There are smaller choices in there that may change flavor text, stats, etc., but this gives me a much better idea of where I want to go with the story. When I create my stats, I think of the kind of challenges I expect my character to go through. I take a lot of inspiration from the Daria series (LoW, LoM, LH1/2/3). I like the idea that the MC can create their own path through life, while still following my preset general idea of how things go. In addition, I like the branching style of gameplay that the original Choice of Vampires offers, and I try to implement little bits of that in.
I think stats give the player a good idea of where they stand within the game. I try to keep my games from limiting playthroughs based on stats, though - I don’t want it to be an auto-fail or you miss out on a huge portion of the story simply because you were 1% too low in dexterity to pass the skill check. There are levels 
In my case, I actually came up with the general idea of the stories I was writing, then I came up with stats I felt would fit, before writing. It gave me an idea of what kind of “failure” and “success” flavor text/scenes I could put in, as well as what type of branches I could write (for instance, there are entire characters in Explosion that you can miss due to, for instance, choosing not to go to the forest and instead go to a neighboring village).
