Only having a single source of income is not a good idea. There are no sure things in life, and a job is exactly one of those unsure things. It does not matter whether you work in a company for 30 years and have an amazing track record. The company will lay you off, if they have a crappy management. Sometimes even if they have a good management. You can never know.
The best insurance is getting multiple income sources, so if one goes bad, you won't be left desperate.
Its fine if you only have a single job but have multi investments that are generating decent profits. That way, even if you lost your job in the future, at least you will not struggle in your finances. However, if you only rely on a single job without having other sources of income, and have not made any investments at all, well that’s a very terrible case. You have to save a lot while working so you can invest in the future, like having bitcoin investment as your retirement.
It's true that there's nothing wrong with having one job and having another source of income, but if we don't have a job but we still have income from the investments we have built then this will be very confusing for people who see us and people might think different things about it. ourselves and for now everyone will try their best to be able to have several sources of income that they can save and also invest, because if we don't have investment for the future of course we will have very difficult times and have to work until we are old and not will be able to enjoy old age by relaxing.