Тhere is a high degree of inflection of nouns, pronouns, adjectives, numerals, case and gender in Balto-Slavic languages. Old English was also inflected, but its declensions simplified as it evolved into modern English. Modern Greek and German have 4 cases. Because there is a free word order, complex case system and high inflection of the words, the use of the articles is redundant.
When I say Slavic languages are highly inflected , I mean they are realy inflected. This is an example of the Russian word ‘to run’ showing declension in different tenses. And Russian is not the most complex language among Slavic languages in this regard.