Steam binds game installations to a specific account where you purchased them;
I don’t know what you think Steam is doing in this regard, but if you have some evidence that it writes personal account data into game files to prevent their use elsewhere, then please share it. That would be newsworthy.
you can’t really argue that it doesn’t behave a lot like DRM would, for practical purposes, and for your typical user.
The only similarity to DRM is that the game expects it to be present. If that made it DRM, your graphics driver would also be DRM, as would your OS, your input devices, and your internet provider.
Obviously, these things are not the same. That’s why we have different words for them.
Please don’t be disingenuous.
Please don’t confuse people by misusing technical terms.
(Or at the very least, have the grace not to complain when someone corrects their usage. Sharing and refining knowledge is how we all learn from each other, after all.)