When to move a sprout from cup to bigger pot

Hi
when i can move my sprout from a small cup to a bigger permanent home pot. How big the plant must be to transplant it? Also i wonder and i need to be answered to why i cant or why is a bad thing to start the grow of a germinated seed in the big pot, why i must sprout it in smaller cups and then to transplant it? its not the same thing,its not the same soil and environment? When outdor and naturaly grow ocures the seed grow without a problem, why indor isnt like this and sprouting in big pot can be overkill? Thanks for the answers.

Bump for an answer please.

from what ive gathered with sprouting in bigger pots is the roots will spend more time to develope so you will initially get slower growth. also it is alot easier to over water in a bigger pot. these plants where started in 5 gallong pots. i had to seperate them, they are almost 2 weeks old. also it is alot easier to control humidity by putting a dome on a smaller pot or a jiffy seedling tray.

Thank you very much for the answer.