Steem and etherium are both decentralized platforms and apps can be built on their blocks.
Steem however, has a lower acceptance rate at present, and also has not been able to move into the bigger leagues.
Also, there is the issue of inflation, since steem tokens has no limit, many questions arise,
Who says that steem tokens has no limit? I think there is a cap on the maximum tokens that can ever be produced.
https://steemit.com/steem-help/@peterz/steem-currency-cheat-sheet
https://steemit.com/steemit/@ntomaino/qustions-about-the-steem-token-supply-10-steem-reward-for-the-best-answer
steem is infinite, it gets a correction every 3.3 years at about 10:1.