"Popularity is important if you want to hire developers" 15+ year vet here. I'd have to disagree. Popularity is important if you want to hire green developers. Not if you want good ones.
If you want to grow a team, you need to hire a mix of experience levels. With younger devs, talent is correlated with being opinionated - they have passion that hasn't been balanced by broad experience. And opinions are fashion-led. Find me a young dev who has no real opinions, and I'll show you a dev who has no taste.