We can be Gospel-centered by talking about God
We can be Gospel-centered by talking about God since the Gospel exhibits the economy of God in accordance with the eternal relations of God and the nature of God.
To say God is good means that he is "the Good" and the source of goodness (see Mark 10:18). And something that is good will share of itself; so the Father eternally shares of his goodness in his Son. The Gospel reflects the goodness of God and his beneficence.
The link between Gospel and God explains how, for example, early Christians shared the same interest in Gospel-centeredness but did so through knowing God (see Jn 17:3).
It also shows a contrast in focus. Earlier Generations focused on who God is and what he does (metaphysics and attributes); we focus on Christ's work and evangelism.
Neither, I would suggest, are necessarily better because they tend toward the same end: making God known savingly. Yet I do see a weakness in ignoring what earlier generations prioritized, namely, knowing God. For that is eternal life as Jesus says in John 17.
While holding fast to the Gospel proclamation, we need to reclaim what stands behind that proclamation, namely, the simple, one, and triune God of Scripture.
That's the only way we can a full answer for "why" the Son came to die for us (hint: John 3:16) and what then this means for us after the point of belief (our growth in GODLINESS).