Stay vigilant about your online communities.
If each time someone engages their post is received with hostility or negative feedback, they will soon disengage and leave.
This behaviour might be done on purpose to chase some marginalized people away, or might be done subconsciously from internalized biases or systemic discrimination.
Sadly, the result is the same.
If you are part of a privileged group, observe how marginalized people are being replied to in your online communities, and use your privilege to intervene when necessary.
Sometimes, just showing a little support or positive feedback can make a significant difference to keep your communities diverse, inclusive, and happy.