Then I guess this is what you get for talking about something without knowing what it is lol.

As another user pointed out, TypeScript is a different language (.ts extension) that extends JavaScript, meaning JS code is valid TS code, but TS adds various language features for type checking. Your editor is then able to interpret your code according to these type structures and warn you if you are making any stupid type errors like this one:

The problem many people have with TS (such as the "big projects" mentioned by Fireship) is that sometimes you end up having code that works but still have to do some weird type gymnastics to please the TS compiler and have it remove any errors and warnings.

That being said, frameworks that "create really weird undecipherable minified JS" do have their place, as they allow you to seamlessy do things that would be either very inelegant and verbose or significantly more complex in vanilla JS, but I won't bore you with an excessively long wall of text.

PS: I love your Czech flag website. Had me jump on my chair when the music started blasting through my headphones.