Firstly, Entity Framework already implements UoW and Repository pattern by itself where DBContext is 1 UoW and DBSets are repositories. Even though, some people still want to implement an other abstract layer of UoW and Repository beyond that, however I don’t want to go more details about this topic here :).

Dapper is on other side, it’s not fully ORM just micro ORM and just focus on data mapping. People use Dapper to focus on performance and simplicity. In theory, you can use both UoW and Repository pattern with Dapper but not too much people doing this way. They usually use CQRS + Mediator + Dapper + consider to use Repository together.