A very fundamental but very critical question is here. "Why do you need to involve users in your product development process?"
I guess you already know the answer. And the answer is related to this term: USABILITY. What is usability, then? As Usability comes Use + Ability, it means that 'your product CAN be easily USED by people, or not'. If a product is very easy to control with its intuitive interfaces, a user of this product will say 'Oh, I'm able to use it'. And it's the same meaning to 'Oh, it's usable'.
So, the usability is saying if a product provides usable features or not. And the judgment about 'it's usable or not' is confirmed by users, not product developers or designers. If users don't like to use the product (or its interface or particular features), then the product is not user-friendly made. Successful products need to be made as it is liked by users.
How to make a product that will be successfully liked by users? Then, involve users in the product development process, and ask them how to make, what they need, and what they want. This is now the basics of product development at a company, and every product developer and designer should know.
Keywords: #usability, #usability testing, #usability evaluation, #participatory design
Useful references
Visit NNgroup (Nielsen Norman Group)'s YouTube channel. They provide a lot informative videos to learn!
AJ&Smart's videos are also very good!
Subtopics in this lecture:
A. Design with Users (Participatory Design)
B. Usability
C. Usability Testing
D. Usability Testing - Case Studies