[carlosdp]

The ecosystem is largely adopting Typescript as the canonical way to write javascript applications now, and having types makes the code more readable. I feel like it makes a lot more sense for tutorials to show things in Typescript, which is what most devs would actually use, rather than lose that type context with pure JS.

[steverydz]

I wouldn't be so sure that MOST devs would use TS. It certainly is popular and dare I say trendy, but I know more people and projects that don't use it over those that do.