As the name implies, the purpose of a proof-of-concept (POC) prototype is to prove your product concept. A POC answers if a product is feasible.
In most cases a POC prototype is only used internally to determine the practicality of a new product. Customers will rarely see a POC prototype.
So do you need a POC prototype for your product? The simple answer is it depends, since there are multiple reasons to create a proof-of-concept prototype.
If you a maker with experience creating DIY projects using development kits such as an Arduino or Raspberry Pi, you are usually in a good place to create a POC prototype for your product.