What about the MLB?
No real salary cap there.....
And real soccer hasn't one either.
Major league baseball has two things going for it where a salary cap really isn't necessary.
#1) Revenue Sharing.
#2) A very strict Luxury tax threshold where if a team's salary exceeds the threshold, they are required to pay a dollar for dollar penalty to Major League Baseball.
You're right, Soccer doesn't have a salary cap, but the revenue structure is very very different. Also, with teams being relegated and promoted every year, you really can't have any sort of fiscal and spending stability.
And look at Juventus right now. Being demoted will absolutely kill them next year, and for a few years after that, without the revenue streams from sponsors and TV contract that they lost this year.
Now, imagine if they had a salary cap in Serie A, and Juventus was demoted. Its bad enough that they lost several players this year, but if there were ACTUAL salary limitations, they would have lost EVERYONE, simply because they would have been WAY over the cap with the likes of Del Piero, Trez, Camo, Buffon.