With top 3 I've come to realize how much of a problem this is with card games in general. Even when you only have 3 cards in your deck, there are games, more frequent than I would expect, where you simply don't draw one of the 3 cards. If that cards is a board clear, or part of a combo, or a win condition (as pretty much all cards in top 3 are), that game is simply unwinnable (even if theoretically your deck should beat theirs).

It is the same with tech cards, but to make matters worse they don't print enough tech cards to even be somewhat consistent. Generally you wouldn't want 4-6 eater of secret/kezan mystic cards in a deck, but if the meta is dominated by secret decks, yeah, you kind of need that many to have a realistic chance of being able to counter it on turn 6. (Same with board clears and zoo. 4+ board clears is normally too much for a deck, but in a zoo heavy meta that isn't enough and many classes don't even have access to 4 good clears.) At least that's been my experience.