'attention scarcity'. Unfortunately that sounds like the talk of toddlers, I mean, attention has to be won with meritorious behaviour, you don't win an entitlement to it by being born. I don't mean to be so abrasive in saying this, but when the pool of attention is so big, and right at the moment, the system is completely wide open, unsegregated, unsegmented. A solution that might help with the non-monetary element of attention, is having groups. But as far as the money and vote rewards goes, the pool of available rewards is limited by the size of the sum of all members' SP.
To do things any other way makes no economic sense. This is also why this platform makes such a strong appeal to anarcho-capitalists, who unlike these modern liberals or the anarcho-socialist types, believe that society should be regulated by economics and logic, and not the illogical and economically ignorant idea that anyone acquires a share of a scarce resource without doing the work that gets people to pay. Besides the injustice of it, the rewards spread so thin that the incentive towards meritorious behaviour is lost.