Google, in comparison, absolutely dominates the search and ad markets and sucks all oxygen out of them to keep any competition from springing up by controlling distribution and limiting choice. They e.g. paid vast amounts of money to Apple to make sure users don't get a free choice of search engine.
If you wanted to compare the Apple Watch with this it would mean that Apple would make exclusive deals with all stores (online and IRL) selling watches so that consumers would only see Apple watches everywhere they go and would need to look in the basement or on an obscure subpage to find any watches from a different manufacturer. Clearly that's not the case.
That said I'm not a fan of Apples walled garden either, I think this should be addressed (and in the EU it is being addressed). It's ridiculous to have this super powerful hardware and I can only run sanctioned apps on them instead of being able to install any kind of software I like.