[{quoted}](name=Metal Janna,realm=NA,application-id=RaE1aOE7,discussion-id=AaUATVOg,comment-id=000000000000,timestamp=2019-08-15T21:46:22.719+0000)
Increased chance to see 1-cost units that you already have.
If you're swapping out 1-cost units for 2s and 3s throughout the game, then the only ones you're going to keep are the ones that are part of the comp you're going for.
Therefore you won't be seeing more Dariuses when you're building Noble or more Nidalees when you're building Ranger, unless you're using those specific champs as stopgaps to cover the lack of a champion you're planning to pick up later.
Ok so you leveled up right? You stand good chances of rolling 2 cost, 3 cost units in each hand now. Why would you keep 1-cost units that you no longer need?
And if you need them for just a while longer but are planning on throwing them out later, why would you mind seeing more of them?
You realize those Garens and Elises sell for exactly the amount you put into buying them right?
Upgrading champions is never a loss. Even if you're only going to be using it for a couple more rounds, it's still good to upgrade a champion to 3*!
This isn't how it works. Take for example, Garen. Garen is great at the beginning, okay in the middle, and nothing special in the late game. This is all doubly true if you don't plan to have items on the Garen. Most of the time I'll pick Garen up and 2 star him to have an early-mid game front line, but I don't want any more of Garen after that. I'll be selling him off and replacing him with Chogath or Sejuani, or some other frontline champion.
And actually, there is a cost to upgrading a champion that you're going to dump anyway. It's up to 5 coins that could be triggering income, up to 5 spaces being taken up on your bench that could have more valuable champions there, and probably worst of all, in regards to your suggestion, it's having champions you don't want wasting your draws when you could be getting better ones.