I read on Wiktionary that
иначе could have stress on the first or second syllable.
- Which pronunciation is more common in your experience?
- Why does such a common word not have a standard pronunciation like most others?
Which pronunciation is more common in your experience?
Ина́че is more common in speech though both variants are equal in terms of orthoepy.
Why does such a common word not have a standard pronunciation like most others?
Actually in Russian quite a few words may have different stresses. In this particular case, I guess, the form "и́наче" was due to Church Slavonic influence.
On the pronunciation. You may find the following excerpt interesting:
Ваше имя в платочки рассоплено,
ваше слово слюнявит Собинов,
и выводит под берёзкой дохлой —
"Ни слова, о дру-уг мой, ни вздо-о-о-о-ха".
Эх, поговорить бы и́наче
с этим самым с Леонидом Лоэнгринычем!
В.Маяковский. "Сергею Есенину", 1926
I wonder whether stressing the first syllable used to be the standard pronunciation and we are witnessing it drawing its last breath today.