The key to real wealth is being a successful employer. There's no better way to generate income than by making money for each hour that another person works on your company's behalf. The challenge is to minimize your risk; many businesses require a substantial initial and ongoing investment, which will always be at risk when the economy takes a dive. And believe me, there's no more difficult or time-consuming job than running your own company. It's nearly 24/7, and when someone calls in sick, or the bank screws up payroll, or your office Internet goes down, or the client arbitrarily changes your deadline or refuses to pay for services rendered, or one employee claims they were harassed by another... Guess who deals with it? You do. Speaking as the founder and owner of a 40-person company, these are just a few of the things I deal with constantly. I have probably aged 15 years in the 7 since I started my firm. As an example, just this Saturday morning, I received an alert that our bank's online wire transfer system had crashed. Payroll was due today at noon for processing, otherwise my people wouldn't get paid Monday. So I had to race down to a local branch -- closed due to Covid. Did 90 mph to get to an open branch. Made it in as the last customer -- since the bank was closing early due to the shelter-in-place order here in the SF Bay Area. Just made the cutoff by 5 minutes. That's what a weekend is like when you own a business. By comparison, my flying job, which I love dearly, is orders of magnitude less stressful and more enjoyable.
Real estate can obviously generate substantial passive income, but most novices think it's much easier than it is. First, if your property is financed, it's almost impossible to generate positive cash flow,; the best you can do is have your
rental income cover your mortgage (which indeed builds wealth through equity), but it'll be a long time before you actually see positive cash flow. Second, the costs add up: property taxes, insurance, ongoing maintenance (groundskeeping, pest control), unexpected maintenance, HOA fees if you own condos, losses from unpaid rents, court costs for evictions, utilities, and so on. I own 11
rental units in 2 states, and if all goes well (ie few evictions, no major maintenance issues), I'll be happy if I can clear 5 % on my investment every year. That doesn't count price appreciation but also ignores the risk of price crashes, like happened in 2008-09 and is about to happen again. And it also sucks up your time. Even with a residential property management company, you're still having to expend time and effort just managing your rentals. It's not really 'passive' although many people call it such.
So yes. Multiple income streams are highly advisable. They're just really difficult to construct.