> is it moving fast enough that the massive investments in data centres will actually pay off?

It may be moving so fast that they do not pay off, i.e. they get commoditized too fast. This all depends on Ai demand in the end. If you can keep the GPUs saturated (at a profitable rate), then it really shouldn't matter how much a token costs. If you bought too many GPUs, or paid to much for them in a hype cycle, you may need higher token prices to ROI than the market wants to pay given alternatives.