In 2012, Microsoft released the Windows 8 and her goal was twofold. First, it wanted to compete in the tablet space, a space dominated by Apple's iPad, and second, it wanted to create an ecosystem based on the Microsoft Store.
Valve realized that Microsoft's success in this category would threaten its entire business model and thus began its journey to establish the company as a platform and not just as a game client.
So in 2013 he announced SteamOS and by 2015 he made a very strong entry into the console space with Steam Controller, Steam Link and Steam Machines. Although this effort was not a huge commercial success, Valve was not discouraged. In 2018, Proton announced a platform to facilitate compatibility that allows Windows games to run on Linux.
Proton has made huge strides using appropriate technologies such as DXVK, which allows games that require DirectX 9, 10 and 11 to run through the Vulkan API. In fact, this particular project has progressed so far that the Amazon is trying to get into the game by offering Proton game streaming through Luna. The progress of this effort is continuously documented on ProtonDB and today they passed a major milestone as user reports on the site reveal that 80% of the top 100 games on Steam are running on Linux and by extension the Steam Deck.
The games in the above image posted by neowin are ranked using a medal system, similar to what WineDB has been using for the last 20 years. If a game has a gold medal, you can expect it to run exactly as it does on Windows. This includes games like Microsoft Flight Simulator, No Man's Sky, Back for Blood, Cookie Clicker, Dark Souls III, Stardew Valley and more.