Numbers in beta were dropping far before Midwinter and HC announcement and mainly because of the staleness of the gameplay thanks to the hyper consistency.I think numbers in beta were dropping because nothing was happening. Homecoming as a new game should have boosted the numbers.
Right now there is quite a large RNG factor. That RNG factor currently decides most of the time who of those equally skilled players will win, instead of small differences between these players in intuition, choices and strategic plays. Even simpler: if you are not so skilled but you draw all your good cards at the right time and in the right combinations, you will win against a pro player who doesn't. Luck beats skill.
But this is not something that can happen in Gwent when you don't draw between turn. Gwent is probably the only CCG without the top deck luck.