You are looking for reasons where there is none.
* Why Brazil speaks Portuguese? * Why do we speak English now? * Why do people in Ukraine speak Russian instead of Ukrainian?
Not because Russian is more expressive. But because they were killed for doing otherwise. It's not about language features, it's about politics, wars, colonization, economics.
[2] https://www.youtube.com/watch?v=CDeujOxl3jc (they are talking about this in the video: [3] https://en.wikipedia.org/wiki/Bykivnia )
[4] https://en.wikipedia.org/wiki/Vinnytsia_massacre
As the policies of Ukrainisation were halted (1931) and replaced by massive Russification approximately four-fifths of the Ukrainian cultural elite, intellectuals, writers, artists and clergy, had been "eliminated", executed or imprisoned, in the following decade. The term was coined for this - Executed renaissance.
Many would argue that Holodomor (1932-33, 2-10 millions of Ukrainian speaking people died) was a part of Russification campaign.