It was not a feudal state. It was roughly similar to post-slavery South in the USA.

~~Yes, I already wrote they didn't "achieve communism". It's the point of my text that they were promising it in the future in exchange for loyalty to a weird system in the present.~~

Sorry, wrong comment.

and forced the Soviets to waste resources on a strong military.

Oh, so it's "the capitalist nations", not the way Soviet system worked, made this so expensive?

But even despite their failings, communism was still the best thing to ever happen to Russia.

Stolypin and Witte are generally considered something much, much better. The closest it came to a normal society with civilization potential.

Unfortunately, Russia was also the worst thing that ever happened to communism.

One could argue Khmer Rouge were that, but IRL communists' incredible ability to just pretend it didn't happen makes USSR the most notable example.