Of course, your opponents get seven cards, too
Additionally, it can grow itself by tapping and paying a small cost to add more +1/+1 counters, making it a low-cost yet versatile card for decks focused on +1/+1 counters
Replace it with something that reduces mana cost rather than eliminates it entirely, like As Foretold or Baral Chief of Compliance
Both decks notably include the Planechase Mirrodin artifact lands, which all cost a dollar or more
I don't know if that's exactly what you had in mind with Skyfisher, but holy cow it's got me thinking
The successful non-Oko decks were heavily tuned toward beating Oko, and its likely that many of these decks will flounder in a more open metagame