They probably could, but I think the risk of directly affecting the normal user experience is too high. That would for example mean that preloading videos will be trickier, and that there is a high chance that there will be a 3 seconds of silence between the ad and the content.
I bought Outer Wilds recently (my consumerism couldn’t resist the 40% sale on steam), friends recommended it and I know nothing about it, but only time will tell if I’ll play the game someday or if it’ll stay untouched for years…