Tbh, I would be pretty frustrated developing any non-trivial frontend code without a type system. But I am interested to try dropping frameworks.
For the projects I've written like this, I've been able to get by with simple JSDoc and an IDE that supports them.
Here's a random example: https://dev.to/ingosteinke/using-jsdoc-to-write-better-javas...
You can always compile your front end code from Typescript to Javascript with something like esbuild.