> Russian grammar is inflectional, yes, but that's about the only difficult part of the language.

That's saying that getting to the lunar orbit is the only difficult part in landing on the Moon. The whole complexity of inflectional languages is in the inflections. It's also why Slavic (or Turkic) languages form such a large continuum of mutually almost-intelligible languages.

Compared to inflections, everything else in Russian is simple. The word formation using prefixes and suffixes is weird, but it's not like English is a stranger to this (e.g. "make out", what does it mean?). The writing system is phonetic with just a handful of rules for reading (writing is a different matter).