The idea of the Data Transfer Object (DTO) is to have a dedicated data class for accessing the API. A mapper is generally used to transform the DTO into Domain data models, which are used by the rest of the app. If your MemeList is simple, then the mapper will also be simple and this is not a large burden.

In this simple case you might be able to use the single MemeList data class for all other uses. If your API is clean and without superfluous extra fields, the field names are reasonable, and the structure of the data is acceptable, then you could get by.

But the idea of a DTO is to insulate your business and repository layers from the details of the particular API you are using, and rely only on Domain layer data models. It is more of an insurance policy against future changes. If the DTO is done correctly, you could change your API provider or change from Retrofit to Ktor and the code changes would be limited to the API code (not the Domain, Repository, UseCases, etc.)