I think Discord has had a huge impact on Stack Overflow as there are many communities created for specific technologies, languages, frameworks, or topics, where most users can get answers from direct contributors or people who have the best industry knowledge on the topic in question.

Not to mention how beneficial it is for brands and products to create such closely-knit communities for their users. There's no need to Google things or ask on SO, as one can chat in real time and go back and forth for solutions with other users.