Well, there isn't too much difference between 7.7M p and 11,160 splatfst points: 1,116 wins in ranked * 5,500p (if you're S) = 6.138M p
I think someone calculated how much time it takes from Lv. 20 to 50. It's supposed to be about 300 hours of Turf or 240 hours of Ranked Matches. That's a lot, but better than everyone sitting at the cap. I actually hope Nintendo increases the cap to 99 at some point. Leveling up from 50 to 99 then would take roughly 6 times as long as from 20 to 50 :D THEN we'll be talking about long leveling stretches.
If you want to level quickly you should play ranked when zones is in rotation. It's the quickest of the three ranked modes, because knockouts happen fairly often.