Should you go for totally new or just improve existing products?
We need to be more careful whenever we use the word "new."
Whether the technology is new or old, doesn't even matter.
What matters is -- do the customers already feel the need? e.g. tooth decay is an old need and thus you don't need to educate the public about it. e.g. everyone wants to look good and thus you don't need to educate them about personal grooming etc.
In contrast, if you are designing accessories for iPhones, iPads etc, you may have to educate customers in some parts of the world on what these products are intended for. Or if you are running classes on creativity, innovation etc, many people may not realize that they need these skills or they may assume that they are already creative, innovative enough.
In this regard, you should even welcome competitors. The more, the merrier. Their very existence validates the market need you have assumed.
However, please bear in mind what Musashi has to say: "Have no preferred sword". Both introduce totally new products and improve existing products as well.