Yes, even if your business has nothing to do with the internet, you still need to invest on digital marketing. I am not joking, I will tell you why.
There is always a certain portion of your target audience that you do not reach. Every marketing channel has a specific reach such as an ad on TV and an ad on Facebook and so on. For instance, you are running the ad of your local business on the TV and it is working well.
Fine, but are you sure that your entire target market watches television? Maybe not. You need to use multiple marketing channels to reach your entire target market. For instance, if you got a halal certification Singapore, you can run a Facebook ad campaign targeting the locals. This way, you will attract people who are interested in your products and use Facebook.
Similarly, you can use SEO to reach those who do not use Facebook but use the internet. You can reach them via Google search.
This is why digital marketing is crucial for your entire business.