I feel the same too. It seems too good to be actually true. Or it a dream of escape from a job that the person never wanted to do. So they think of retiring early and escape the pain in a dream.

For those who are passionate about what they are doing, they would continue to work on their fields even after they retire.

If they are actually contributing to their field of work, they will be paid well, they will have the enthusiasm to continue their work and their mental health would not worsen.

Still investing should be done along with work side by side but it does not necessarily mean that everyone can retire early, most of them can never do this.