Well... lets see here. The Royal Collection Trust as a collection is owned by Elizabeth II and overseen by the Royal Collection Trust. The Queen owns some of the collection in right of the Crown and some as a private individual. This is the entity that has well stocked "trademarked" gift shops and even an online website store. The profits help to maintain this collection. Notice too that the website says "Official Royal Gift Shop".
https://www.royalcollectionshop.co.uk
Waitrose Duchy Organics are also sold at an online store and as stated earlier, it was founded in 1990 by The Prince of Wales to not only promote his passion of sustainability but this "marketing" also puts profits into his Prince's Trust endeavors which helps so many different people.
https://www.waitrose.com/ecom/shop/browse/groceries/organic_shop
Both the Queen and The Prince of Wales have not let these ventures detract from the job they're to do. Should Harry and Meghan go this route, its possible then that with it being tied to their foundation, they wish to take more time to work with it, establish it and lessen the "Firm" side of things and be "junior" rather than "senior". I don't know. None of us know. What this all does tell me is that "marketing" and "branding" isn't something new to the people that are trying to work all of this out with the Sussexes.
To quote Alice, things are really getting "curiouser and curiouser" ?