Nobody cares if a solar panel is 2% efficient if it costs 100 times less to fabricate and install. Just build more of them. Still, it is good news to see this sort of energy research bearing fruit.
Panels at 2% efficiency would be wildly uneconomical at practical any price.
I guarantee that is wrong, if the price got low enough it would be economical. Wikipedia suggests to me  plants operate at 3-6%, and plants are extremely economical. Even starving African children can afford access to plants. If solar panels were as cheap and easy to produce/distribute as plants but could be plugged in to a grid then 2% efficiency would be wildly economical - it would be the greatest energy revolution in human history.
It doesn't require that much imagination to say that solar cells might one day be work in an extremely similar fashion to plants. Not likely, but not an outrageous thought.
Nature has produced a cheaper, more ubiquitous and more self-replicating solar system using efficiencies in the 5% range with a theoretical cap of 11%. That suggests we don't need 25% efficiency to accomplish amazing things. It isn't a critical metric.
The biofuel is burning what amounts to the plant's surplus energy that it wasn't using for anything, and recovering some of the energy that went growing the mass of the plant. It isn't comparable.
The point here is plants are covered with tiny green solar panels that are grossly inefficient compared to what humans produce. However, they are beyond cheap to produce (in fact they grow themselves) and suggest that we are not even close to pushing the limits on what we can do with solar energy design wise.
Efficiency of the solar panels really isn't all that important compared to making something with the flexibility and weight of a leaf. Comparing efficiency between solar panels is a waste of time outside the research community; all that matters is total cost to install vs. watts produced.
I use a modern portable solar panel that's in the realm of ~25% efficiency when camping, and I certainly wish it were smaller for the same output. I'd be willing to pay more for that.
There's obviously segments that care more about efficiency than cost, not all solar applications have unlimited space.
You can see even at utility scale the panel prices are generally less than 50%. I think 2018 increase was tariff related. Been out of the industry ~5 years so don't follow stuff that closely. Many of the other costs are basically a multiple of # of panels which would be 10x at 2% efficiency.
And that was the point - weight and difficulty of transporting the final system is a very important variable. Probably more important than efficiency when orders of magnitude are concerned. From a 25% base efficiency can double and double then it stops improving. Weights and installation costs due to the panel technology can halve and halve and halve and so on - and each halving reduces the cost of transporting the panels. There are more gains to be made there. It would be worth trading efficiency away to make big gains there.
I think Perovskites are interesting because they are cheap and can get you 25% efficiency in a single layer cell.