Most certainly marriage as an institution is not perfect. And luckily in the modern world being married isn't a requirement. Ton of people live with their partners and don't marry or remain single. It's all personal preference in the western world.

Saying all that, in my observation and experience the only people who complain about insititution of marriage or insist that society pressures them, are in two categories. One is unhappily married people who are afraid to leave or dependent on their spouse and can't leave. Second are people who have hard time finding a partner or good partner or partner who wants to commit.

I know many happily married people or in good relationships and they don't think marriage is a sham. Those who don't have that or aren't even married believe (or say that they do) that marriage is a sham. It's kind of ironic.

Something tells me that if opponents of marriage met someone really great today and were proposed to, they'd get married tomorrow. All this "society pressuring them or marriage is a sham" wouldn't matter as much.