Interest is still an incentive but now a very small one and curation is an incentive but only if you're willing to power up a lot to compete with the bot voting which is impossible for anybody with a job/life to compete with without becoming a bot yourself. And then user engagement drops.
Other incentive is to determine where the author rewards go. All of these require a huge power up to be serious. There is no incentive to power up as much as you can afford (which is a lot less for most people). That's why I'm powering down. It's just money sitting there. I can hold steem speculatively but I won't be powering it up until I feel like it could make a difference.