From their perspective, the purpose of your work is to enrich their platform. The difference is in the distribution of payout and work conditions. Rather than having a stable 100k salary at said company, you have the chance to earn absolutely nothing, or be an outlier and beat the 100k. Is it worth it, by expected value? Well, according to the article numbers,
Expected Monthy Payout = 24%0 + 23%50 (using half of max of ranges) + 22%500 + 19%5000 + 9%50K + 3%200K (using double the greatest lower limit)
Which gives an expected monthly payout of $11,600. Not bad! I think 30% of this goes to the respective platforms, so an expected yearly salary for an app developer might be something like $97,500. And I believe this matches up fairly well with what companies are willing to pay app developers (on average it seems higher, aside from maybe in the Valley).
What's interesting is the distribution of payoffs into the "haves" and "have nots". There are few app developers pulling that $100K or so salary. Instead, two thirds of everyone is below poverty, and a select group are killing it. This seems to be the new modus operandus of the tech economy. The implication is obvious: extreme economic inequality (especially as non-tech jobs become less relevant), which by necessity will increase social inequality.