When I brought half life 2 there was a lag of about 2-4 years before I could play it for the first time - I didn't read the fine print, and on a dial up connection I couldn't get past the steam client updating in a reasonable amount of time, mind you I was able to download much larger Linux ISOs over time frames of a month+ through resumable downloads.

Not really an issue these days but it certainly was back in the day

Steam's DRM is still an issue today and it means that you have to get cracked copies of most of the games you paid for in your library if you expect to ever own them. I spent some months without an internet connection only to find the steam games I'd been playing offline just fine suddenly refused to launch until I allowed steam to phone home to grant me permission to play the games I paid for. Steam could go out of business at any time and all your games would simply stop working.