@oleg_guryanov thanks for the comment. I just realize that my question could have two different meanings. I agree that if the product design isn't helpful to build something lean, it should be a blocker. Honestly, my question was if finding a product designer can be an issue to launch something due to lack of them.
@jin_kwon Finding a designer is not an issue on resources like Upwork or similar. For something more challenging there are agencies that design great apps.