I'm looking to make a substantial income without hiring single employee? I am ok with freelancers but not with employees. If yes, what are those businesses?
Absolutely! In fact, this is where many solopreneurs "max out".
With the Internet, as long as you have a flow of traffic of interested prospects, you can keep converting and selling, right? There's no limit at the scale an individual can operate on to that flow.
As a consultant, if that's what you choose, you need to move beyond "trading time for dollars" as soon as possible. Staying stuck in that mindset is how most consultants hamstring their revenue.
> work with high ticket industries so you can charge high fees in line with the value you are creating
> get your own products (courses, physical goods) out there for sale ASAP
> always be looking to expand your distribution channels to expand your revenue sources.