This article mentions all kinds of trends correlated to stoicism, but it completely failed to explain causation.

Stoicism gained recent popularity because it directly opposes other trending cultural perspectives, such as self-victimization dialogues surrounding mental health and self-accountability for survival under capitalism.

The topic is promoted by red-pill commentators because they are leveraging it to argue against societal complaints coming from other people whose needs are portrayed as “weak” or lacking accountability.