TypeScript won, but not how you think.
In 2015 I was still slinging ES5 and jQuery. TypeScript felt academic, with triple-slash refs and a compiler that yelled at me. Most startups I touched wanted speed, not types.
Back then, adoption was a rounding error - think 1-5% of devs touching TS, based on early surveys and npm noise. JavaScript owned basically 100% because, well, everything compiles to it.
By 2020 the tide flipped. React, Angular, and VS Code made types feel natural. Stack Overflow and State of JS put TypeScript around 25-35% regular usage, with JavaScript still near 70%. Refactors stopped being gambling.
2025 feels like the default changed. Most greenfield React/Next projects I see start in TS. Call it 45-55% of developers using TS monthly, while JavaScript remains universal as the runtime. npm installs for typescript grew by roughly an order of magnitude since 2017.
Why the shift? Scale, IDE superpowers, and now AI pair-programmers that thrive on types. Angular baked it in. Next.js nudges you there. Even the Bun/Deno crowd treats types as table stakes.
Caveat: these percentages come from surveys, GitHub/npm signals, and my own battle scars. TS doesn’t replace JS; it disciplines it.
My rule: small scripts, plain JS. Anything with teammates, longevity, or refactors - TypeScript. It’s not trendy. It’s insurance for Future You. 🚀