
I've been feeling the same way and it was almost too simple for me. First, strongly typed languages are objectively better for catching errors during development instead of during production so a small amount of work upfront pays huge dividends later. But the easy part is how actionable it is.
Find a codebase that you want to convert. For me, it was a server that I wanted to convert to Firebase cloud functions to go serverless. I took my server.js file and copied it as server.ts. I created a simple tsconfig.json file in the root with some standard settings online and then I let the VS Code IntelliSense guide the migration. It was so much easier than I expected and I learned TypeScript as I was converting my codebase.
It was almost too easy and now I have all of the benefits of feature-rich and built-in assistance in my code-editor. Documentation on hover, clear and clean errors. This was only about 2 weeks ago and I am not sure I'd ever go back to Vanilla JS now. It was love at first use with me.