How to focus TCG Game on completing collection and not on battling?

Hi,
I am designing this single player TCG game. The player will have a small open world where they battle other NPCs and collect Cards. Battles will have an important role but i want that the goal of the game is to complete the card collection. Battles will be there to get money for booster packs and cards. But i don't want that the player just opens boosters to get better (thats a side effect ofc) but mostly to finish the collection.
In most oldschool tcg games there is an tournament or something similar and the goal is that the player wants to win it. The focus is clearly on batteling in those games.

How to communicate it better to the player that the goal is to finish the collection? What feature is important so that the player wants to finish the collection? What should i add so that the player is more happy about opening the pack at the end of the battle and getting new cards, rather than just getting the good cards?

Edit: A lot Underwood me a bit wrong or my post was not as clear on that: Battles will be an important feature. The game will be about battles. But similar to the old Pokémon games(not TCG) which also were about battling they also were about collecting. While my game will have an interesting battle mechanic with very nice card effects, I also want it to have this magical feeling of collecting that those Pokémon games have. When opening a booster the player should be also very happy that they got 2 new cards, even if only common cards, rather than just paying attention to cards their deck needs. But I don’t know how to get this feeling into my game.