You can purchase the game in a web browser and use steamcmd, which (one could argue is still requiring an app) to download and install. In cases where the publisher is not invoking DRM (Larian games like BG3, DoS2, etc. for instance) once the game is downloaded you can certainly archive it and transfer it to another machine and run it there without Steam. In the end you are likely purchasing proprietary software (though again it’s not always the case on Steam) and we could say you don’t really own that either, so maybe take your complaints to the publishers or just use the power of your wallet and not buy those games and support libre games, of which there are many, another way. That said, Valve is actively making things better for users by developing and contributing to useful libre software like Proton (WINE, DXVK, etc) that can work outside of Steam.
I remember the “old days”. That was when dialup internet was still popular and running a server usually meant it was on your 10Mb LAN. When we got DSL it was better and you could serve outside your LAN. This was also the time when games had dark red code booklets, required having a physical CD inserted or weirdly formatted floppies (sometimes a combination of these). You could get around these things and many groups of people worked hard at providing these workarounds. Today, many of these games are only playable and only still exist because of the thankless work these groups did. As it was and as it is has not changed. Many groups of people are still keeping games playable despite the “war” that corporations wage on them (and by proxy on us). Ironically, now that there is such a thing as “classic games” and people are nostalgic for what brought them joy in the past, business has leapt at this as a marketing opportunity. What makes that ironic? These business are re-selling the versions of games with the circumvention patches that the community made to make their games playable so long ago. The patches that publishers had such a big problem with and sought to eradicate. This is because the original code no longer exists and the un-patched games will not run at all on modern hardware and the copy-protections will not tolerate a virtual machine. Nothing has changed.
We can even go back as far as when people first started making books or maps that had deliberate errors so that they could track when their work was redistributed. Do the people referencing these books or maps benefit from these errors?
Why do some of us feel compelled to limit knowledge even at the cost of corrupting that knowledge for those we intend it for (and for those long after who wish to learn from historical knowledge)?