+1 to this; it's an experience that's especially punishing and common for new players.
In terms of the minion restriction, some of the comments below capture it well. But in addition to the visual complexity, the bigger reason is actually in the mental burden of large boards in a world where your opponent gets to choose who does/doesn't block.
Using MTG as an example, I've played a LOT of it for about 15 years, and I still frequently have situations where I've got 10 units on board, my opponent has 10 potential blockers, and it's too much for me to figure out. So I'll just swing in with everything without much thought and hope for the best.
With this new rule in place, we'll feel more comfortable going wide in creative ways moving forward, but we'll do our best to avoid putting players in situations where they are just blindly swinging because all the possible combinations are overwhelming.