In 2012, Microsoft released Windows 8 and its goal was twofold. First, it wanted to compete with 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 taken huge strides in using appropriate technologies such as DXVK, which allows games that need DirectX 9, 10 and 11 to run through the Vulkan API. In fact, this project is so advanced that Amazon is trying to get into the game by offering game streaming Proton through Luna. The progress of this effort is constantly being recorded on ProtonDB and today they have surpassed a significant milestone as user reports on the site reveal that 80% of the top 100 games on Steam run on Linux and consequently on Steam Deck.
The games in the image above, published by neowin, are ranked using a medal system, similar to that used in WineDB for the past 20 years. If a game has a gold medal, you can expect it to run just like Windows. This includes games like Microsoft Flight Simulator, No Man's Sky, Back for Blood, Cookie Clicker, Dark Souls III, Stardew Valley and more.