Nobody says 'id est'. In fact, there's only a tiny proportion of English speakers who even know what 'i.e.' stands for. If you're reading aloud a text that includes 'i.e.', you say the two letters - pronounced "eye ee".

You spell the letters, so you say "eye ee".

I read it as "eye ee," and I've heard people read it as "eye ee." You do not ever read it aloud as "id est." However, I think Carlos has the right idea. "I.e." sounds unnatural when spoken. It is mostly used in print, and even in print it is old-fashioned, formal, and pedantic. Unless it is important to read something exactly as written, I think it is very reasonable to "translate" it and read it aloud as "that is."

just say for example

“I.e.” is used informally just because it is so short. Just saying the letters would usually be understood, as would translating it as “that is”. Of course you wouldn’t use it in more formal speech.