I exclusively run Linux and I play modern games all the time without issues. You just click "install" on Steam and it works 99.9% of the time; I dont even look up the game to check if it works anymore. Also, have a look at some comparisons on YouTube — some games actually run faster on Linux because there's less bloat in the OS.
What distro are you on? Some don't install all available KIO workers and you'll have to install them yourself.
Is this something that is likely to improve going forward?
Like any FLOSS project, things tend to happen when programmers decide to solve a problem for themselves. If you don't the the skills to do this, you could always bring it up on the KDE forum under the "brainstorming" category, submit a feature request on the KDE bug tracker, or sponsor a developer to perform the work.
I'm making a joke in poor taste to express my disdain for people who commodify human necessities for profit.