I think technology makes many people lazy. With spellcheck many people just accept whatever word is shown, not knowing if it is correct or not. People's vocabulary is getting smaller.
With that said there is a huge upside to technology. Machines of all kinds are becoming more efficient. Medical advances are amazing.
As to when we became dependent on technology, that would be when mankind used their first tool. Technology is not new. It evolves as it progresses. It is as important today as it was yesterday, as it was last year, as it was last century, as it was last millennium, as it was in the beginning of mankind. Without it we become stagnant.