Do you feel content warnings are beneficial?
Nope. Quite the contrary.
But it may be worth mentioning I'm getting old (nearing my 60s) and I have been educated in a now remote time where the idea that being confronted with hardship and with failure is what would help us learn to overcome them. Not being shielded from them.
do you thing there are better ways to address dark topics?
Confront shit ideas with better ideas. The rest, any form of censorship or control, never works, never did and I doubt will ever.
Heck, aged 16 my best friend and I decided to read Mein Kampf in order to understand how that 'Nazi' stuff managed to seduce so many people. While we were reading it, as seriously as we would have read any other book, we just discussed it freely meaning without fear of being judged ('being cancelled' one may say nowadays): we would point out stupid shit as well as things that seemed not, to young us at least, not that stupid trying to confront them through a free and open discussion. Decades later, I can safely say it was one of the best cure against me ever risking getting 'seduced' by those shit ideas and the hate they thrive(d) on.