This is an architectural limitation. The Marketing Cloud OAuth 2.0 integration in CRM Analytics uses SOAP API to retrieve data. Content Builder Email assets are only accessible via REST API. Because these are two different API protocols, the existing integration cannot retrieve Content Builder content. To include Content Builder assets in your CRM Analytics data, a separate REST API-based extraction process must be implemented outside of the standard connector.
Salesforce Marketing OAuth 2.0 Connection
https://orgcs.lightning.force.com/lightning/r/Knowledge__kav/ka0Hx0000022V5LIAU/view
000394797

We use three kinds of cookies on our websites: required, functional, and advertising. You can choose whether functional and advertising cookies apply. Click on the different cookie categories to find out more about each category and to change the default settings.
Privacy Statement
Required cookies are necessary for basic website functionality. Some examples include: session cookies needed to transmit the website, authentication cookies, and security cookies.
Functional cookies enhance functions, performance, and services on the website. Some examples include: cookies used to analyze site traffic, cookies used for market research, and cookies used to display advertising that is not directed to a particular individual.
Advertising cookies track activity across websites in order to understand a viewer’s interests, and direct them specific marketing. Some examples include: cookies used for remarketing, or interest-based advertising.