Will there be a bet on prediction markets for how low the yield will be ?
What do you mean? Yield is a function of the chip size and density as well as the process. Plus it's a commercial secret so your bet can't be adjudicated.
As soon as China can get their yields up, they will go all in on exporting these. Until then, they will subsidize them for domestic use. So you can kind of tell where they are by what they do with the chips.
Yield is generally not an issue over time, at least not as big as someone outside of the industry would think, if you get enough chips to work in the first place. For high volume chips, fabs will tune their process specifically for your chip over time. And you can do mask changes just to address yield problems and you can add redundancies if you have to. For example Huawei is no longer bottlenecked by the quantities of chips they can get for their handsets. Their problem is that they can't get the performance they could get with a better process.
It is both really. You can easily have performance or you can have yields, but what you really need is both.
Performance is generally limited by the process. Yield not so much. Assuming you can make it at a meaningful level at all, yield is generally a learning process.