next.js: IE 11 support not working with TypeScript

What version of Next.js are you using?

latest

What version of Node.js are you using?

14.15.3

What browser are you using?

IE 11

What operating system are you using?

Windows

How are you deploying your application?

next start, next dev

Describe the Bug

In my application IE 11 support is not working. JS code breaks with errors, since the code is not transpiled properly. This can be reproduced with the example app https://github.com/vercel/next.js/tree/canary/examples/with-mobx-state-tree-typescript

just run the app and open it with IE 11

interestingly, this app works fine in IE 11, despite also using TypeScript https://github.com/vercel/next.js/tree/canary/examples/blog-starter-typescript

What is the difference between those two, i.e. what is causing the first example to fail?

Expected Behavior

The example https://github.com/vercel/next.js/tree/canary/examples/with-mobx-state-tree-typescript

should work in IE 11

To Reproduce

run

yarn create next-app --example with-mobx-state-tree-typescript with-mobx-state-tree-typescript-app
cd with-mobx-state-tree-typescript
yarn dev

then open http://localhost:3000 in IE 11 and look at the errors in developer mode