Wholeheartedly agree. No one wants to be the Cadbury of their craft, as a freelancer. That’s creative hell.
One caveat I’d add is that when we talk about the context of a mass market product — product design instead of design as a service—this changes.
There’s no shame in working on a Cadbury, IKEA, Toyota, H&M, Wizz Air. When working on these “lowest common denominator” products, you can make an impact just by making them a little better.
Having said all that, I’ve worked at “lowest common denominator” companies before, and nowadays work at a small Whitaker’s style digital agency, and I’m far happier for it.