No matter how hard you try to have all of your calls answered each time the phone rings, such an ideal situation may not happen all the time. There are some days in business that are busier than others, and the calls will be left on the line. Hence, you can also use your voicemail for reaching out to clients and marketing activities like cold calling.
Website: https://www.versum.com/m/blog/setting-the-best-voicemail-messages-for-your-beauty-salon/

The bottom line is that a business’s situation is likely to change often and rapidly, each of which need a unique and applicable voicemail greeting to cover the circumstances and timeline. For example, callers shouldn’t reach a business-as-usual voicemail, and therefore expect a return call within the business day, if the subject they’re calling is out on vacation for two weeks. Such a lack of communication is a recipe to lose that caller’s trust and tarnish the brand’s reputation.
Callers aren’t going to spend time sitting through a menu that doesn’t let them, at the very least, leave a voicemail. If a caller knows their party’s extension number, an option can, and should, be “Press 1 to leave a voicemail,” or something along those lines. That way, clients can feel as if they’re expressing their concerns without needing to talk to an agent, and without the agent feeling sorry they couldn’t pick up while they were working on something else.