With respect thats a total assumption on cuban people's livelihoods. They have free and subsidized access to many quality public services, a cheap cost of living and unemployment is very low. Of course if you want to be a millionaire you wont stay in cuba. But who needs that when every basic need is provided for them by society at large?
Your assumption that communism means a 16 year old shelf stacker gets the same as an expert of sorts in their thirties is a myth against communism. Who ever said you cant earn more money? Its the old story about the coal miner on 19 roubles and the doctor on 20 roubles. The doctor tells the commissar 'you have to pay me more money than him. people will die if im not around' the commissar says 'well i mean if people dont get coal they'll freeze to death. people will probably die with you around pal. theres 20 roubles for you. shut up!' The point is you can earn more money if ye like, but who needs vast wealth? Who needs to be a millionaire if they can have a good income, do a job they love and have good quality public services for most of their basic needs? Who needs to own a house if they have a lifelong state lease on 50 quid a week or less? I have argued we should have a maximum wage for our public servants and a taxing of all private sector workers at 51.5% above 80k. I dont see why people shouldnt pay high tax if they earn more. 37'000 people earn over 150k. 20'000 public servants earn over 100k. Just a few reforms and crumbs to keep ordinary people happy wont end waiting lists, build CF units or give everyone an adequate wage.
You might argue the point of working is for an adequate income. I would say it should be for loving what you do as the income should be part and parcel of your job already. Hospital consultants wouldnt be asked by people like me(if we ran the show as they say) to work on 8.65. But they wouldnt be taking home 250k either. The cap of 65k for all public servants and 150-200k for all private sector workers would ensure adequate wage levels for the more qualified and at the same time we could have a much higher minimum wage for those at the bottom.
BTW as a keynesian you should know the law for full employment. its called reaching 96% of people in work. Its inevitable with seasonal workers, people switching jobs and the underemployed and some disabled workers who only work part time that we would be paying welfare at any rate. BTW of all the nordic countries, only Denmark and Norway have real equality so thats not a perfect system either by any means. Just ask the icelanders q'ing for slice pans or the swedes who've had dole cuts.