Are steam deals really better than on other platforms? They might have better deals compared to brick and mortar retailers but publishers generally have price parity across various digital storefronts (eg. epic vs steam), so attributing low prices to steam doesn't really make much sense. If anything steam is actually more expensive if you factor in authorized keystores (eg. greenmangaming), which are occasionally cheaper.

A 15–20% fee would be much fairer in my opinion. They’d still be making plenty of money while letting developers keep more of what they earn through their hard work. At the very least, they should differentiate between big players and smaller indie developers.