PC Gaming

Everything runs on an API, including steam.

The simple fact that Epic allows API proves that they not tracking and datamining people's information

That's not how anything works. Even literal spyware would have to make use of some APIs. The acronym literally just refers to a interactive protocol between software applications.

AFAIK, legendary, the python application which Heroic uses to interact with Epic services was created by reverse-engineering the Epic store API used by their launcher, not by implementing some public spec they freely provide. It's essentially a workaround they haven't bothered shutting down. For now Epic hasn't blocked it, but that's not the same as an endorsement.

Legendary may not have implemented the parts of the Epic launcher that collects user data, but that doesn't mean Epic doesn't do that.

I mention Linux, because that is the primary use-case for Heroic. I entirely forgot it works on Windows.

I'm under no illusions about how Steam works, but to claim EPIC of all companies is any better, is beyond rich.

GOG I can agree with, but even they have some games that don't work quite right without galaxy. That may improve, as those APIs are being reverse-engineered, as well.

Steam maintains the right to erase a user's game library without a refund

So does GOG and Epic. The only difference is that there's a third-party downloader for their libraries.

All three storefronts sell at least some games with executables that function entirely on their own, no launcher necessary once the game files are acquired.

All three also sell some games that can be shut down by their respective developers or publishers, or rely on other services that may not stick around.