All the people trying to sell you something else. I heard someone on HN call it "blog driven design". Tech blogs need something to write about, Udemy teachers need something new to sell, startups need some way to differentiate themselves from their competition, so they start talking about how awesome [insert new tech stack here] is. The cycle continues and in 6 months, [new tech stack] is old news and you can't build the modern web with it and it doesn't scale, so here's [even newer tech stack].

Meanwhile Ruby, PHP, Python, and Java are still powering all the sites that are telling you those technologies don't work anymore, and powering the site that takes your money when you buy another Udemy class to learn [even newer tech stack].