Look at the healthcare system of cuba

Yeah but at the same time LGBTQ were prosecuted, so it's healthcare is not for everyone.

or the rapid improvement of living conditions in the ussr after lenin took over.

Yet the system wasn't protected against someone like Stalin. And also under Lenin things were grim for many.

Again, the idea of communism is great, it just doesn't work in the form we've seen. So far the best form is (and I hate to say this) China I think, with a partially open market and the average lives improved significantly. But also China has a one party system with one leader with too much power who can stay in office as long as he wants, also known as a dictator. Next to that they have workers with 7 day work weeks and no holidays, concentration camps and an insane amount of corruption.

Coming back to Cuba, they are also not doing great.

Maybe Cambodia is an example of a functioning communist state, although the wealth gap there is also insane and they had a dictator not too long ago (Pol Pot) with a pretty severe genocide. And with the recent whistle blowers on Chinese scam centers in Cambodia and Myanmar (which got it's slave workers through Cambodia), also a vast network of corruption came to light reaching as far up as ministers. And also Cambodia isn't a proper communist state, even though they do identify as communist.

I wish there was a new version of communism in which there are protective measures against tyrant leaders and corruption.

After the fall of the USSR most states who became Independant kept the system of the USSR. They continued with corruption and a non-functioning system (as the vast network of the USSR wasn't there anymore). Estonia did not. They completely rewrote their entire system, switched to digital and became the world leader in cyber security and low running costs while having a properly functioning system. Maybe we could make a state built on that, but then out of communism?

But I prefer no states at all and anarchism.