The variance still plays a role, regardless of whether you see your whole deck since there is still measurable effect on the probability that you see card X at click T. More so, a 46th card adds more variance than a 61st. E.g. the probability that you’re holding a PPVP in your opening hand decreases by about half a percent. If we were to chart average credit pools between 45 and 46 card decks we would probably see the 46 card deck lagging behind slightly. Now, it’s possible that the deck is fairly insensitive to such a difference, but there is also the possibility that such a lag can have a butterfly effect due to how scoring windows work.
Your feature game was just quite atypical and should not be used as evidence. I modelled your accesses very precisely using an agnostic model that I just recently developed (viewing accesses from the perspective of the runner without the “eye of God” spectator advantage). You “found” 5 agendas when my modelling predicts 7.15, so you were actually quite unlucky in that game.