First things first.
The working world is not linear.
Putting in a solid 8 hours of input does not give back 8 hours of output.
A software developer working 8 hours a day is not getting the same output as a construction worker working 8 hours.
Three factors need to be leveraged to extract more money for your time.
What: is your choice of service, is it in high demand or does it provide leveraged returns for the buyer?
Without a high-paying skill, you'll be spinning your wheels. Exhausting yourself with extra hours, only to be taxed on most of that come payday.
Who: is the buyer and do they have the means to pay high rates for your service? It doesn't matter how useful you are if the people you're selling to can not afford to pay for your service.
Will you be viewed as an investment or a cost?
How: How easy is it to hire you and get the job done? Where will these people be able to find you? Is there a marketplace for your service?
Highly paid knowledge workers are similar to athletes.
They train hard, then sprint, then rest and reassess.
Then they train some more based on feedback and sprint again.
Rinse and repeat.
By seeking feedback after each sprint, you create a non-linear output.
You can make small tweaks to what you're providing to make it more valuable for the next sprint.
You're not going to earn life-changing money by renting out your time at a 9 to 5.
A large majority of people get about a 5% raise each year.
After inflation and after moving into a slightly nicer apartment, that raise is already at a loss.
Lifestyle creep destroys the rat race loyalty.
To make real money, you need to own a business or part of a business.
The definition of what a business looks like is changing.
You can be a solopreneur, a freelancer or a contractor.
A one-person business selling a solution or a result.
This is where the non-linear output works its magic.
Instead of being told what you're going to be paid by an employer, you set the rates based on the result you provide.
The more valuable the result, the more money you can charge.
The more skilled you become at providing this result, the faster you can make money.
The rise of the gig economy shows that many businesses would rather contract out certain requirements.
Finding, interviewing, training and paying an entire team just to provide a specific task in-house is expensive.
Being able to hire people on an ad-hoc basis and just pay an invoice for their service is easier.
Technology is making gig work easier to find and provide.