A loud, resounding ... YES!
It's a direct line of communication directly to your customers.
It allows you to easily share what's going on with your business. Things like sales, events, new product launches, and more.
It also gives you the ability to grow and maintain a relationship with your customers. This is accomplished by sharing helpful content and insights as well as asking for questions and showing you're there to support them.
Also, email marketing keeps your business top of mind. By being in their inbox every week or two, you're letting people know you still exist in this crazy world and that you're ready to help!
Take note - just because you have your customers' email addresses, doesn't mean you should abuse this line of communication by emailing them every single day or by asking for too much ... don't forget, they can unsubscribe whenever they want. So, you don't want to push it.
At the end of the day, I believe ALL small businesses need to use email marketing to keep in touch with their customers.