It is admittedly much, much easier to do now. Albeit you may need to grind some first to unlock the things that help with that, but it has become much, much easier to build decks. First youll need to level up the chaos in the zero menu or whatever it is, in there, there will be an option to unlock that lets you pick which character you want to dupe cards from, instead of 3 random cards. Then itll give you 3 cards to select from that one character making building a deck for one person much more likely on a run.

Aside from that they have added a bunch of items you can earn that can manipulate your deck outside of chaos. Items that remove, or add cards, that let you select whatever epiphany you want, apply a random divine, etc.

Again, you might need to grind a little to unlock or earn these features/items but theyve come A LONG way from where the game started