First, sorry if I'm not using the correct terminology here.
By "word-based", I mean typical Indo-European languages (plus Uralic) where there are only tens of characters (e.g. "A to Z" (Latin) or "А to Я" (Cyrillic)), and a character alone has no meaning, unless it happens to be a complete word ("I" in English is both a single letter and the nominative first person singular pronoun).
By "character-based", I mean languages like Chinese and Japanese, where any single character has its specific meaning.
I have wondered that, how would a word-based language to exist with absolute zero word inflection. A word inflection is like the plural form of a noun, or noun declension by case (Latin, German, Icelandic, Finnish etc.), or verb conjugation (Romance languages, East Slavic), or affix-based adjective and adverb distinction. Periphrastic affection doesn't count (e.g. Perfect "tenses" in English, which is constructed with auxiliary verb "have").
In Chinese, there's absolutely zero word inflection. Nouns do not have plurals or declension, verbs do not vary by tense or person, and they don't even have participles. This, IMO, relies heavily on the fact that Chinese is a character-based language.
English, AFAICT, is the language with the least word inflection features among all Indo-European languages. Nouns have at most 2 forms, and verbs have at most 5 forms (except "be"). Adjective only has one inflection (-ly turns into adverb).
How would such a language be, if word inflection fades away utterly?