This. While the Russian Empire was unable to really start assimilating Ukrainians before the 1900s or so (because almost all Ukrainians were peasants, and almost all peasants were still illiterate in the 1890s and had little to no contact with the imperial culture), the USSR was very much a literate country as early as the 1930s, and an industrialized and urbanized country by the 1960s. From the 1960s on, most Ukrainian children have been spending more time at school and before the TV screen (and now the computer screen) than with their parents and grandparents. Have all school instruction, TV broadcasts and newspapers switched to Russian for a few decades, and that's it for the Ukrainian language, at least outside rural localities.It has had, yes. However, many people speak Russian, and still identify as Ukrainians and support the Ukrainian state (it's like the situation with the Irish people and the English language), while there are also people who speak Ukrainian (usually heavily influenced by Russian), identify as Russians and Ukrainians at the same time, and support the Russian state in this war. One Aleksey Mozgovoy (Oleksii Mozhovy in Ukrainian) was even a singer of Ukrainian folk songs for a time, before joining the Russian-led forces in 2014 and becoming a prominent frontline commander. That is, linguistic and political assimilation sometimes do not coincide.