Is it worth spending time to collect Bitcoin rather than having a daily job?
No, not worth it, work in real life, and just invest in bitcoin... There is no real substitute in having a day job and having a steady income... Risking your money if you want to invest in bitcoin is like betting in gambling with the price, too unpredictable...
What I mean is that can bitcoin be more economical?
Nope it's not, on the other side, if you have problem going out to work suffering deductions due to late/traffic congestion on the streets in where you live, you could really try home based jobs but do not focus well in bitcoin, try other jobs...
Has it ever happened that people lose their investment value rather than benefit from spending it on bitcoin?
I haven't heard any, but who will tell their stories in forum where success is the only talk of the forumites... Probably many just silent about it and just doing their best right now to make a success story...
Anyway, OP, do you have a day job?