Yep, I understand.
But then there is the flip side that a Lexus dealer see's a lot more of the same type of cars and has access to Lexus technical knowledge and documentation that an independent never will. As an example I wonder how many independents are aware of the high pressure fuel pump recall and the reasons, and that is quite a public piece of information.
This is an interesting thread and good debate as there are pro's and con's to both approaches.
Myself I hate using any garage(independent or main stealer) and would rather do all work myself as then I know everything has gone back correctly and nothing has been damaged in the process. But for my RCF i do use Lexus just for servicing to keep the stamps in the book.