Consumer confidence is declining, small business expenses are rising, and gas prices remain a concern for household budgets. Whether you own a business or work as an employee, the economic picture can make the future feel uncertain.

Millennials are feeling that pressure acutely. Glassdoor's latest report found that 76% of millennials are actively questioning their career paths, and 68% have delayed a major life milestone because of career uncertainty. Their response is a strategy called stability stacking.

Glassdoor defines it this way: "Stability stacking is a career strategy of layering multiple sources of security — such as skills, options, income, and networks — to ensure that no single job, boss, or industry disruption can knock you flat."

One of the most important layers in any stability stacking plan is a side hustle. Even three to five hours a week on a side gig can add meaningful income each month. According to a LendingTree survey, roughly two-thirds of side hustlers say their life would be unaffordable without the extra income it brings in.

Extra income and financial stability are not the only reasons to start a side hustle, though. Here are five other ways a side hustle helps you build stability and create opportunities for career growth.

1. A Diversified Portfolio

Even people with seemingly dependable income can benefit from a diverse portfolio of income streams. Diversification means you are less reliant on a single income source, and less likely to take a huge financial hit if one stream dips — or disappears entirely.

2. New Career Pathways

A good stability stack means you have options. In practical terms, you have the luxury of choosing a new pathway to go down, and a side hustle can help you get there. If you start a side hustle in an industry totally different from your main income or career, the skills you learn can open you to brand-new opportunities and career pathways.

3. Less Reliance on One Employer

Stability stacking through a side hustle means you may rely less on your employer or other main income streams. ZipRecruiter found that side hustles give job seekers bargaining power. Job seekers with a side hustle are far more likely to reject a job offer (49% vs. 32.2%) and to say they would quit without another job lined up (46.9% vs. 23.6%).

4. Grow Your Network

A Deloitte survey found that more than a third of those with a side hustle said it helps them develop important skills and relationships. You will naturally meet new people through your customers, clients, or other people in your industry at networking or business events. The relationships you build can create opportunities you may not get through your day job alone.

The stronger and larger your network, the more opportunities you have access to — which is especially valuable if your circumstances were ever to change.

5. Increase Earning Power

With the new skills you learn, you may even have an opportunity to increase your earning power, since side hustles give you a chance to learn skills that are in demand in the job market. For example, Upwork's Future of Work Index found that freelancers who offer AI-related services earn 34% more per hour than those who do not incorporate AI.

Side hustles are popular for the extra income they provide, but they can be much more than that. They are a core part of stability stacking, or building a stronger financial and career safety net, and can even open pathways you might not have otherwise seen. There are plenty of side hustles to choose from, so check out some popular ideas and start stacking.