WordPress.com is just one of the companies that offers you specialized wordpress hosting. all companies that do that come with some restrictions or surprising pricing plans when you compare to “regular” hosting.
Since those companies have their own specialized enviroment in which wordpress runs, which they rarely reveal the details of, it is hard to compare between them and self hosted wordpress. The distinction is usually mainly about not having to maintain the server level processes and the specialized wordpress support.
So in principal the 299$ you pay to wordpress.com is for some extended tools like caching and CDN and support which specializes in woocommerce. Does it worth the money? maybe for people that lack technical knowledge to handle hosting by themselves or people that don’t have it in house and do not want to depend on freelancers.