Communism doesn’t work on a large-scale, and it’s not sustainable.
Have you ever heard of little thing called “economy of scale”? The bigger scale is - the more sustainable it is.
By it’s very nature it’s extremely prone to abuse, and fundamentally impossible to install any sort of checks and balances on a single party-system.
“checks and balances” do not prevent abuse. They are not designed to.
Look how bad it is with a two-party system in the US.
In my opinion two-party system is worse than single-party system and full pluralism. In single-party system there is only one party to blame, while in many-parties system no party can control discourse. While in two-party system both parties can agree to screw over people and finger-point at each-other, only creating illusion of pluralism.
And that besides societal issues two-party system creates like strong polarization.
while in many-parties system no party can control discourse
As someone living in a country having many-party system, the discourse is perfectly controllable in the same way they are doing it in US, just with tiny extra effort. Since 1989 we didn’t had even a single anticapitalist party in parliament despite having sometimes over a dozen of them for several years. Hell in current term we have the most parties - 17 parties + 42 independent parliamentarists on 460 seats in sejm, and still what we hear from all of them is similar on every base question - no alternative to capitalism, neoliberalism in practice, and complete submission to USA and EU in all manners.