That dictionary documents es-, is-, and ēs- as common pronunciations (perhaps IPA vowels ɛ, ɪ, and iː), with the 'es-' form (short e sound) most common in the U

That dictionary documents es-, is-, and ēs- as common pronunciations (perhaps IPA vowels ɛ, ɪ, and iː), with the 'es-' form (short e sound) most common in the USA (this is the one I generally hear people use, with a vowel sound somewhere between IPA ɛ, e, ə, æ sounds and short enough that identifying the precise vowel can be tricky) and the ēs- form (long e sound) most common in the UK. Having multiple accepted pronunciations is different from “most people mispronounce this”. I don’t really understand what you are criticizing. Maybe you can put up an audio recording including what you consider the “correct” and “incorrect” pronunciations to be?