When you bought software at a retail store, the vendor didn't get the full retail price. It's not the platform getting a cut, it's the store. What we need to ensure is that platforms can't force you into their store.
As far back as the 80’s there were means of distributing software without paying a retailer a commission on every sale. Shareware [1] was one such model. The software was distributed by users copying it from floppy to floppy, handing it out at user group meetings, conferences, even on the school playground. It was later included in large CD-ROM collections packaged with computer magazines.
The point is that you could distribute your software any way you wanted to without permission or license fees paid to the maker of the computer or its operating system.
You as the Shareware author were paying for the creation of those discs and their distribution. If you had an FTP server, you paid for the bandwidth.
Epic isn't doing that. Epic wants access to Google's customers, with Google paying all the bills, without paying Google anything. Despite the fact that Android allows them to run their own app store or sideload apps.
Shareware disks _could_ be written and paid for by the shareware author, but user-to-user distribution, at the _user's_ cost was [seemingly] more common.
I recall my local independent PC shop in the mid-90s had a big assortment of shareware on 5.25" floppies, priced per disc. Similar offerings existed in mail-order catalogs. The disc provider made a small margin per disc, presumably, and it created a different distribution network for the shareware copies, in an era pre-ubiquitous Internet.
A few years later, there were shops that specialized in burned or pressed CDs of Linux/BSD distributions back when dialup was the standard and fetching a few gigs of Debian was out of reach.
I think this might be more compelling if Epic were the ones hosting the download, and Google were just like, listing the download in their listings, where the download button would go to Epic's servers.
Oh, for sure, I didn't mean what I said as a dismissal. It seems like it could be a reasonable state of affairs for Google to just link to (and sign?) it, but not host it.
The point is that you could distribute your software any way you wanted to without permission or license fees paid to the maker of the computer or its operating system.
[1] https://en.wikipedia.org/wiki/Shareware