Is it worth spending time to collect Bitcoin rather than having a daily job?
Your daily job will be the one to provide you more funds to reinvest in bitcoin so I'd rather to do both. As they say, your day job will help you get by everyday but your part time job (bitcoin in this case) would make you rich.
What I mean is that can bitcoin be more economical?
It couldn't be more economical with its astronomical growth these past months imo.
Has it ever happened that people lose their investment value rather than benefit from spending it on bitcoin?
Most of the people who have lost their fund are engaging in trades and have made a bad call, but for hodlers, this will not be the case.