Why is Lord Vishnu considered the supreme power?

Why is Lord Vishnu considered the supreme power? The reason why Lord Narayana is considered the most sacred among all scriptures is because he has no Tamoguna (the mode of darkness). That is why he is placed in the middle of the Trinity because he is very calm, happy and composed. He is in the middle of Satvic and Tamasic. He is neither too much happy, neither too angry. In fact, it is quite rare that Vishnu gets angry. Brahma and Lord Shiva also have some mode of darkness but that doesn’t mean that they are impure. If a class teacher is given the department of teaching the most noisy class, does that mean that the teacher is noisy? Same is the case with Lord Shiva. One example of this is that when Bhrigu Rishi had to test the Tridev, only Narayana passed the test. Because he kept calm even when Bhrigu Rishi kicked him but Shiva and Brahma got angry. That is why in Puranas, Narayana is said to be the supreme is because he has no mode of darkness (Tamoguna). Hari’s body is transcendental and blissful, he is the most handsome god among the trinity. But if we dig deeper, we will not be confused because originally it is Sadashiva who is the source of Mahavishnu and all the names of Vishnu are of Shiva alone. It is due to the boon of Shiva that Vishnu is glorified in scriptures. Hence, if we say Vishnu/Brahma/Krishna is the supreme, it is Lord Shiva alone who is being glorified by different names and forms. Vishnu, again is the form of Shiva hence when he is worshipped, it is indeed Rudra being worshipped.