Long term royalties in Steemit blockchain are not possible currently. Around 1 million steem are miners daily and distributed among all the post published in a day (24 hours) or so. In one year you will have to distribute the same quantity of steem among 365 times more post, so each new post will be receiving a lot less rewards as time passes. It tends asymptotically to zero rewards payment very fast...
If you keep the rewards of authors high in comparison with curators, IMHO the only possibility for steem is to decrease in value trending to zero. It is just the equivalent to long term royalties.
Do you prefer 75% rewards of 50 votes, or only 10% rewards of 1000 votes?