I can tell you as a ESL teacher in Taiwan, time is not the issue. I have students that literally spend 20 hours a week studying, cramming vocabulary for years.... but they still can't speak or write very well. The important thing is to have an interest or a motivation.
Right now, I'm learning German in a class full of Chinese students. My goal is to be able to pass A1 by the end of the semester. However, this teacher and students aren't motivated to learn. They are still "stuck" on the first few pages of the textbook. Meticulously memorizing each word and yet when I ask them "How are you?" They have to pause to think of the answer.
I ALWAYS ALWAYS ALWAYS tell me students if you don't use it you loss it. So, if you learn a new word that you think is pointless don't waste your time memorizing how it works. Also, I believe accents are one of the most important things. If no one can understand you, why learn a FL to communicate with others?