Check here:
Nordeus - Press - Top Eleven reaches 100 million registered users Even if there would be 10m, I doubt they will offer 50m tokens for free every season.
Counting like you said, they will have to give over 650.000.000 tokens per year / 1500 tokens = 100e, I really doubt that
Maybe another way to reward like you said, jerseys or logos will be better but I still think is ok how it is. They can reward players for other reasons.
Your idea is the oldest possible because everyone was looking for this, everyone is looking for more free tokens but is not gonna happen.