Hi Gregory, thank you for your comment.
In fact, not all of these artefacts are needed in every product development initiative. For instance, I would recommend a PoC when a product depends on a technology that is not proven or validated yet in the particular context; if there are no such ‘unknowns,’ a PoC is probably not needed. Similarly, if the level of uncertainty involved in the product concept is relatively low, experimentation through prototyping may only add limited value.
When building a new product, there is experimentation and concept testing (utilizing combinations of PoC, Static or functional Prototypes, user research, etc.), which eventually leads to the first instance of the product (ideally the MVP). The release of the MVP signals an ongoing product development phase — a continuous improvement process via new or improved features. The latter may also involve experimentation, prototyping, etc. Thus, the team must always select the artefacts that best serve the learning needs for each particular case/ moment in the product dev cycle.
I hope this answers your question.