So, the definition "money you get your hands on" definitely isn't correct, and the way to make this clearer is to think of it in terms of credit card processing

So, the definition "money you get your hands on" definitely isn't correct, and the way to make this clearer is to think of it in terms of credit card processing and merchant accounts: if you sell a $5 product and the credit card processor takes $0.25, your revenue is $5, not $4.75, and they actually will report the full $5 to the government as part of a 1099-K and then your job is to report that full gross income and deduct the fees you paid. They also will report any sales you made which were refunded, and you would then separately report deductions for that also. Now, that said, one can actually use that construction to argue that the store is then having revenue, and giving a royalty to the developer or something, and in fact my store did something where I sometimes modeled it as a retail storefront of licenses I purchased wholesale, but these are just not normal models for how the word "cut" is then applied: most people reasonably--and I think correctly--believe that the user bought something from the developer, with the store acting merely as a middleman payment processor charging a "fee" or taking a "commission" off of every sale (and I am pretty sure at least Google even models it directly in that way in its reports; there are a ton of advantages to the store to doing that, and I think even Apple sometimes reaches for this model). From such standpoint, and to look at this using descriptive linguistics, you simply don't ever see anyone say "Apple recently increased the cut of smaller developer's from 70% to 85%": every single headline I've seen says "Apple recently decreased their cut from smaller developers from 30% to 15%".