It could also be a supply/demand issue, generally price increases are caused by either 1. demand increasing, or 2. supply decreasing.
In this case we can interpret a shorter lifespan as decreased supply, but it can also be because the demand for GPU compute has gone up. I think in this case we're seeing a bit of both, but it's hard to tell without more data.
We could also consider the supply / demand elasticity changing, f.x since demand has become more price inelastic it could result in a higher price.