Maybe we don't. But that doesn't mean we can't.
You need an evidence to stand behind such statement. Like: we did that in that, that and that season. Unless you dig an old year I doubt we'll see many such signings. I personally don't recall many during my fan era.
We opt for players like Vidal, Pjanic, Cuadrado, Costa, Berna, Dybala etc. It's clear that we always chase best players from our league (Alen made a good post not so long ago when he said how we wouldn't even sign Pjanic or Dybala had they played in Spain or England). Other than that, we're in a good position to sign faded stars who need to be revived or just generally useful and good players.
I highly doubt our board thinks like "we'll skip on Griezmann so we can sign D.Costa" just because we think he's a better player. We're not even in the race for players when City, Psg, Real and Barca are after them. Such players would never come, or rarely would, maybe just in a case if they are fans or something.
What you say literally sounds like: we can win the champions league, but we won't do it.
