The cost of data storage and sending was a lot more in 2003 than it is now. Where costs have reduced steam has just added more and more features for consumers and developers.
I can't think of any "feature" Steam has added since cloud saves that have impacted me. Any feature development seems to be focused on VR (I don't have PC VR, nor room at my PC to use VR) or streaming (I don't want to stream my game to another device, I just want to play on the PC). And in the meantime their client has stagnated, looking identical to how it did a decade ago, and even functioning the same (e.g. the practically nonexistent library curation features). Hell, even their TOTP app is still the same piece of garbage that they originally shipped years ago, not even supporting 5.5" iPhone screens, let alone the iPhone X form-factor.
