In 2006, digital game sales were unheard of. In the good ol' days I had to pirate pay $50 for a new PC game! But when Steam introduced their marketplace they discovered that creating digital sale events significantly improved revenue.
For a long time, my entire teenage years and into college, Steam was the only way to get PC games digitally. So they were winning. But over time, as we've seen with the TV industry (cable was the only way!), publishers started creating their own stores with exclusivity deals (GOG by CDProjektRed, EA Origin, Epic Game Store, Battle.net, etc.). Add to that the proliferation of indie game development and publishers, today selling on Steam has become a race to the bottom.
What does this have to do with creating developer content?
Something that's "trendy" in the tech world is like a deal event – it's in the zeitgeist, awareness is high, people are searching for material, and they're willing to check out anything that seems to be related to the topic – why? So they feel like they're part of something. So they can mention it to their friends, or participate in conversations.
All content requires prerequisite knowledge to comprehend (Computers -> Web Development -> JS -> React) so when that knowledge is fresh in people's minds due to a current trend, then it lowers the barrier. It can be easier to get folks to read your content.
Just remember while an ingredient on sale saves money it doesn't save cooking time – trendy topics still take work to make content for and if you're not choosy with what trends you chase, a race to the bottom might be happening under your nose.
Have a lovely day,
Kamran