Earlier quoted context omitted.
This type of empty fear mongering comment is unhelpful at best. It's a McDonalds of a comment. What's a lot of people? Why are psychedelics so special compared to anything else (sugar, Facebook, gambling). "It doesn't happen to everyone, but it's common" - what does this even mean? "Common" based on what criterion? How should our behaviour as a society change based on your comment?
Are you comparing psychedelics to sugar and social media? Unless psilocybin is thoroughly tested and validated as a treatment that is as safe as SSRI, I don't think it's really worthwhile to jump into the psilocybin train.
Apart from that, there's the massive list of side-effects, many of them extremely common.
Complete loss of libido, erectile dysfunction, or worse, your libido is unchanged but you completely lose the ability to orgasm.
Insomnia, cause that's what a depressed person needs, even less sleep and more time for rumination in bed.
Akathisia, which is an uncontrollable need to move your body, think restless leg syndrome but it's your entire body. You literally cannot sit still.
Less life-destroying but still very obnoxious: increased sweating, dry mouth (which can ruin your teeth if you don't manage it with biotene or gum or something), blurred vision, headaches, the list goes on.
This is without even mentioning the risk of serotonin syndrome yet, which can straight up literally kill you if you don't make it to a hospital. It happens when your serotonin level is too high, and can cause seizures, fever, arrhythmia, or death.