Respectfully, I suggest avoiding saying this kind of thing to someone who may still be recovering from depression. There's a tendency to want to make what they are going through relatable, but that risks minimizing the severity of what they may be dealing with.

Imagine having lost a family member and hearing from someone, "well, everyone loses things". There's orders of magnitude difference.

I just know from experience that when I've been depressed, the level of futility I have felt about any dissatisfaction in my life was so much worse than when I've been mentally healthy. I'm really thankful for more than a decade free of that level depression.

As an alternative, I suggest simply sticking to statements that are affirming of how they have described themselves feeling.

I understand. My point is that you never reach a perfect place because your goal line keeps shifting. It's easy to undercut your view of your own progress by noting you aren't where you want to be. There is only ever "in progress," and that's OK.