This question can lead to a huge discussion
Well, as the tendency in the world is to use smartphones and computers, and if you can't find company's website or any social presence, you just can't trust it. It might be only my opinion, but I believe there are more and more people like me every day. So having a website nowadays is a must-have. If you want to stay updated, save your old customers and gain new ones, you should have a website and promote it.