"Abusing their dominant position" feels a bit far... the competition is just 💩 IMO. Just the fact that EGS practically gives out games for free, and still struggle to penetrate the market, should tell you all you need to know.

Steam provides discussion boards, workshop (mods), cloud saves, a whole console (deck), frequent games sales, achievements, best-in-class refund policy, regional CDNs for faster game downloads, and the list goes on. They even still support the Steam Link box which was discontinued several years ago.

They pretty much go above and beyond the current offerings of any other gaming platform, and have outlasted failed ones like Games For Windows. In the rare case that they do go out of business, there are steam emulators to run your games as long as they do not implement any additional DRM.

It says Valve "forces" game publishers to sign up to so-called price parity obligations, preventing titles being sold at cheaper prices on rival platforms.

EGS exclusives are worse, locking a whole other platform out for an entire year. With Steam's agreement surely you could just run the sale on both platforms at the same time? Anyway, Amazon is well known for doing this, why not take them to court instead?

enabled Steam to charge an "excessive commission of up to 30%", making UK consumers pay too much for purchasing PC games and add-on content.

The 30% fee is a bit high, but looking at everything that it pays for, and the contributions to open source, I don't think it's too bad. Publishers are also the ones choosing to price their games high, and to create as many DLCs as possible to increase recurring revenue. The ones who want lower fees already sell on EGS IMO...