Recognize that it’s not about women or sex; it’s about socialization and respect. Everyone wants sex sometimes, the fact that “incels” want it too isn’t pathological. The pathological thing is not having the social skills to deal comfortably with social interaction or the ability to find love, respect and social support from others.
So, if you don’t want your kid to be an incel, be present for them and kind to them so they learn that they’re worthwhile.
Make sure your children are socialized well. Encourage them to go play with other children. Encourage them to talk to those of the opposite sex. Encourage age appropriate coed opportunities (clubs, sports, summer camp, etc.)
Teach them to share. Let them pursue their hobbies and interests. Teach them politeness. Be a nice parent and a positive role model.
Ensure them that rejection is a normal part of dating and to not be discouraged. Tell them that porn is not a representation of how most people have sex.
If your child sits in their room all day and doesn’t have any human interaction, they have no idea of how to act around people. This makes them undesirable. Their own undesirableness can make them bitter and lead them down the incel road. I’ve never seen someone who was socialized well become an incel.
There doesn’t need to be a special “anti-incel intervention”. Just the same love and self-esteem building that parents have always needed to aim for.