You say “erb”, we say “herb” because there’s a fucking “h” in it.

HUSH. WHAT ARE YOU DOING? WHY ARE YOU TRYING TO APPLY LOGIC TO THE ENGLISH LANGUAGE?

(Although the British have no moral high ground when it comes to logical pronunciation. I lived near Burough tube station and they pronounce “burough” like “‘burr - uh” whereas Americans pronounce it like “burrow”. Although the word “burough” itself is pretty ridiculous even by English standards. So idek which is the more logical way to pronounce it.)