Probably the more likely explanation is that the general individual has slowly withdrawn from society due to the internet.
Plus these groups are addictive by way of being bubbles - where your real life friends might tell you that "hey that is rude" or just wont appreciate you being derogative to others, like minded online individuals will embrace that part of you. And as you become more radical, IRL people will avoid you to avoid your toxicity while you will feel good in the similarly toxic environment.