>do I really need to implement the Into<T> trait and use x.into() to do a conversion? Isn't it better if I just write the function that I'm using explicitly?

Firstly, you would implement From rather than Into. Into is blanket-derived for From. So if B implements From<A>, then A also implements Into<B>.

And no, you don't have to do this. If the function is never going to be generic, there's no sense in writing it that way. Solve the problem at hand, you can always go back and add abstraction later.

I really like Rust. I hear people say that it's hard, but I don't think it's harder than the problems it solves.