The reason for that is due to the number on the card going above the official number of cards in the set
Assembling four different game pieces and then hoping that your opponent either had an exerted character with enough willpower that you could keep swinging into them, or enough individual exerted characters, to win the game in one turn was too much to ask
The 60-card minimum means that youll need to build out a couple of different strategies in your deck, and if you have more in your deck (if there are 204 cards in Chapter 1, you could have up to 816 in your deck, after all) then youll need to strategise even more
You can obviously run Curiosity too, but Commander is all about synergy
Mind you, Im not a hardcore CCG player, and I dont usually seek these experiences out, but Ive got a few friends who play these games competitively or judge competitions, and I trust their assessment based on the Lorcana starter sets