To be fair, we only hear of their deaths because they're basically celebrities. Niche celeberities, but their deaths get reported on by various media sites, particularly those dealing with the porn industry.
On a whim I decided I'd check if there's any real data on suicides by occupation and found
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. Unfortunately, it only gets as specific as "Arts, Design, Entertainment, Sports, and Media" so I'm not sure how relevant it is (the rate's a bit above average for what it's worth).
Regardless, if it is true that porn stars have a hugely disproportionate suicide rate, it's not too hard to understand why. It's an industry where the two most valuable traits you can have are looks and a willingness to do some things you're probably not gonna be proud of. The producers are going to constantly seek to push your boundaries to the limit on the latter trait. Age catches up with you on the former trait. There's an inherent stigma around your willingness to even partake in the industry. And it can be very difficult to pivot away from once you've established yourself.
But most porn stars never quite "establish themselves." The front page of PornHub or whatever is mostly dominated by 20-somethings you probably don't recognize operating under an alias if a name is even given. So they can make a quick buck and bury that chapter of their lives relatively easily.
This post is already way longer than I intended it to be so I'll just end it there.