People stay together for reasons such as status, wealth, or genuine connection.
Status- or wealth LTRs often involve people seeking to fulfill their needs rather than experiencing genuine love and respect. These relationships can be tumultuous, characterized by a lack of respect and diminished femininity.
In contrast, genuine connection LTRs involve mutual respect and femininity from her, but individuals may meet their needs independently.
Both types of relationships can last a long time, but only the individuals involved can determine whether staying in the relationship is preferable to being single. Ultimately, it is a personal choice.
Consider my cousin, who is in a LTR with his high school girlfriend. She chose him because he is set to inherit her father's company. They had children (primarily to bind him to her) and subsequently married and merged their finances. He resides in her home, and she covers all expenses, including vacations. She has secured her "survival" and cultivated the "image" of a respectable family woman. However, their relationship is not based on mutual affection or chemistry.
In this situation, the man benefits from financial security and an easy job (earning well while doing little). However, his masculine needs remain unmet. Additionally, he is subservient to her family.
If he were to cheat on her without her knowledge, it would still be wrong, but at least he would be fulfilling his own needs.
He remains in the relationship because he possesses sociopathic/narcissistic tendencies and enjoys the associated "status" people give him, because of the name of the business. But he know he has not value to his own eyes.
Maintaining independence is essential.
Being in a genuine LTR, also.
He will eventually realize that he is unhappy.
If he desires to be a man, this is not the path to take.
You need to be the captain of the ship, not a member of the staff.