Nothing wrong with sexual objectification.
No. Per the American Psychological Association, sexual objectification -- depicting people as "de-personalised objects of desire instead of as individuals with complex personalities and desires/plans of their own" -- is linked to depression, disordered eating, low self-worth, suicidal ideation, diminished cognitive performance, diminished sexual health, greater tendency to evaluate women's value as only stemming from sexual desireability, and more.
it is a natural part of life
Sex is a natural part of life. Sexual desire is a natural part of life. Sexual objectification in the context of a television program is the denial of agency to the character being framed by the camera -- the depiction of them as entities that exist to give pleasure (implicitly to cisgender heterosexual men). That is not natural and its impacts on people are deeply harmful.
people male gaze, female gaze , have sex and make love.
That is not what the term "male gaze" refers to. The term "male gaze" is a term used in film and television critical analysis that refers to a specific way of framing and depicting female characters in a film or television show relative to the assumed interests and desires of the male audience. The experience of a man looking at a person he is sexually attracted to is not a "male gaze."
Star trek also gave birth to slash pairing, which was about the sexual objectification of kirk and spock as a romantic item.
Once again, sexual objectification is not the same thing as sex.
You can absolutely depict sexuality in a film or television program without objectifying the characters. You can get quite sexy in your show without objectifying the characters! The White Lotus is a very sexually-charged program, but its characters are not objectified -- they all have agency and are not depicted as though being sexually pleasing to men was their primary goal in life.
SNW is sexualised. I would say the sexual objectified characters are Tpring, Spock and Chapel and to a some extent Pike.
No. None of these characters are sexually objectified because none of them are depicted as lacking for agency. They are not beings who exist for others.