Edit: it got fixed, thanks to the author

I think with majority of TypeScript projects using Prettier, 2 is more likely to be the default[0]

The linked page literally says to ignore it [1]

> STOP READING IMMEDIATELY THIS PAGE PROBABLY DOES NOT PERTAIN TO YOU > These are Coding Guidelines for Contributors to TypeScript. This is NOT a prescriptive guideline for the TypeScript community.

4 is a historical thing used as a default for all languages in VSCode [2]

[0] https://prettier.io/docs/options#tab-width

[1] https://github.com/microsoft/TypeScript/wiki/Coding-guidelin...

[2] https://github.com/Microsoft/vscode/issues/41200

Edit: found the TS style guide at https://github.com/basarat/typescript-book/blob/master/docs/... , it should be the correct link

P.S. did send a mail to author hopefully they fix it