Except there wasn't any arbitrary imprisonment. That's just something you pulled out of your ass and keep repeating. Just like in any system, some people ended up being detained wrongly. It's on you to show proof that more people were systemically than under other systems. It certainly appears that US wrongly detains far more people than USSR ever has.

If you think the communist system is better, why did it fall?

Plenty of capitalist regimes fall all the time. Using your logic that's sufficient reason to abandon it yes?

Why do people risked getting shot crossing the Berlin Wall from the east, and Cubans crossing the Carribean, than the other way around?

Why did vast majority of people not do this?

If life is better in communist system, why did so many emigrate despite guaranteed and free basic necessities provided?

They didn't, very tiny percentage of people leave communist systems, and it's never to get basic necessities. I guess we've already established that you don't even understand basic concepts like per capita.

Do you just want to get free stuff to wilfully turn a blind eye to state repression?

No this is just an idiotic thing you keep repeating because you think it's a really clever gotcha. You're clearly ok turning a blind eye to repression under capitalism though since it's the system you keep defending here.

Have you spoken to former detainees under your capitalist regime?

Do you have a job?

I do, and I almost certainly make more than your dumb ass.