I think the whole fast vs slow thinking is also a bit tied up with kind of like "raw intelligence" vs "trained skill". I think there are some people who are really really smart and fast thinkers, and some people who are less smart and slower. But the thing is, being smart doesn't mean being right. Especially as things get complicated where methodology or background research become critical components of getting the right answers. Knowledge is probably more important than intelligence in the application of knowledge. Intelligence may be more important in the discovery of knowledge, and even then, it require the sufficient patience to acquire prerequisite knowledge in the first place.
I'm not sure that one is better than the other, but I suspect there is a lot of frustration embedded in mismatching what you want to be doing vs what you are good at.
Honestly my comment is moot I think
I realised I was coming back to the thread to edit in new thoughts. This means I do both fast thinking (initial comment) and slow thinking (returning to add something else)
I no longer believe I'm solely a fast thinker, I just wasn't giving myself credit for the slow because I'm impatient af
As an on again off again anxious mess, maybe I think fast so I can have multiple answers ready in case my first isn't good enough? Maybe my thinking will slow down over time (in therapy, anxiety is one of the things I'm working on). It's a hypothesis anyway.
If that is the case then at the extreme ends fast thinkers within INTP don't believe in themselves and slow thinkers do. Fast thinkers are cups half empty (and will likely fall on the floor if I'm not careful) people and slow thinkers are cups can be refilled later people.
It kinda checks out to me now I've typed it out haha.