With an increase in apps and programs that help you design, I feel like it's time for me to explain why it's important to hire a designer. I have absolutely nothing against these apps, but that said, this is NOT the same thing as hiring an actual designer.
When you hire a designer, you're getting years of experience, history and knowledge. Designs are not just based on what looks pretty but rather, what will draw the eye in, keep the viewer engaged and build trust to continue reading.
You are guaranteed full customization that is unique to you - so no one else will have the same design. A professional designer will take time getting to know you and your brand as well as doing the research on your industry and competition to ensure you stand out of the crowd.
Personally, your designs aren't a simple task, rather one I pay careful attention to. There is no other way to describe it than simply a magical experience that brings all the elements of your business together under one roof in a professional manner.
Now that said, for quick items like Social Media Posts, I actually train my Digital Marketing clients to use apps to help them out. However, there have been numerous times in these training sessions where people have been shocked to say the least by the way I see things vs them (and that's where those years of training and experience come in).
So my advice, weigh things out. For important branding hire a designer, and invest in a digital marketing strategy that will help you understand the apps and keeping your designs "on brand."