Types can be optional. Also you can commingle JS and TS in the same project. There’s this thing called ts.config.js with lots and lots of options. Typescript is highly valuable for full stack development where you can share types between back end and front end, and less valuable for the front end. If you have a component that you want to be reusable that requires some back magic voodoo with generic typing then just use JavaScript! No reason to force yourself to use it to make everything the same .tsx extension. It’s totally flexible!