I don't see this as embarrassing. It's about businesses reaching customers. That's not what X is used for. I read news, I read opinions, I read governmental announcements, and I follow the discussions of all of these.
X/Twitter is/was used for many different things. Why are you speaking for an entire service?
As a business owner, I did use Twitter to reach customers.
In other words, is Twitter a market? That's kind of a crucial distinction when discussing the Digital Markets Act.
https://www.theverge.com/2014/9/8/6120079/twitter-commerce-b...
https://www.nbcnews.com/business/consumer/twitter-testing-ou...
The current iteration, Shop Spotlight: https://ads.twitter.com/shopping_manager
Second, the "Digital Markets Act" has no "you must sell products directly to consumers" requirement. https://en.wikipedia.org/wiki/Digital_Markets_Act - look at the list of "Core Platforms Services" it covers. Search engines, communications, ad networks - Twitter's absolutely in several of those categories. It's about regulating gatekeepers to the market.