While maintaining an open source project can be fun and fulfilling, it can also be very stressful. Maintainers who struggle with the demands of their role often lack supprot to address the problems they're facing.
Things which contribute to maintainer burnout include:
Many of the things that cause burnout can be fixed if caught early enough. Unfortunately, many people have a hard time noticing, acknowledging, and speaking out about their emotional experiences. This is especially true for men, who make up a disproportionate share of open source maintainers. Rather than addressing problems while they're still small, many maintainers will "just push through", only acknowledging the strain they're under once it has grown unbearable.
At this point, such a maintainer is severely burned out. Fixing the problems that cause burnout can take significant additional effort—effort that a severely burned out maintainer is unlikely to be able to give.
This can lead to the dispiriting petering out of what once was a vibrant and beloved project. Even worse, it can lead to the loss of a once happy member of our open source community.