Would you say that men are portrayed as much more interesting than women in the novel?They are mainly presented only in relation to men.
This is an opinion question. You need to decide what you think, which it appears you have done, and then find evidence in the book to support your thesis.
In locating your demonstration that the men are portrayed as being more interesting than the women, you might compare the ways in which the characters are described. The initial description of Daisy tells very little about the actual person.
an enormous couch on which two young women were buoyed up as though upon an anchored balloon. There were both in white...I've heard it said that Daisy's murmur was only to make people lean toward her
The introduction to Tom, on the other hand, presents a very detailed picture of the man.
a sturdy straw-haired man of thirty...two shining arrogant eyes...Not even the effeminate swank of his riding clothes could hide the enormous power of that body...glistening boots...great pack of muscle shifting when his shoulder moved
The life histories of the main characters could also be contrasted. Daisy, prior to the time period covered in The Great Gatsby, is a teenaged debutante who enjoys flirting with the military officers until she marries the enormously wealthy Tom. Jay Gatsby, in his life before the book takes up the story, runs away from home, attends college for a time, develops the idealized fantasy about who he was and who he is going to become, sails the world, and becomes an officer in the Army.
Support for the opinion you expressed in your comment would be plentiful.