For bandwidth, it’d absolutely make sense if a game that’s 10GiB+ because uncompressed audio and pre-rendered cutscenes (and likely huge day-1 updates) had to pay more of a cut to its platform than a 200MiB (or less) game. Particularly if the smaller game doesn’t even have multi-player.
That explanation makes a lot more sense for AAA who are very likely using significantly more bandwidth (due to data bloat in their games, day-1 updates), and are much more likely to be making millions.
For indie not so much, and it seems odd that there isn’t even some general incentive for games with lower requirements. Then again, using a platform like itch instead (possibly geared more towards bundles) or even going with some other payment method (donations) might just make more sense in that case.