> it is unlikely that open source models' capability will ever surpass frontier models

Sure about that? Would you invest in products almost no-one can buy?

otoh, maybe China stop releasing their best models

Yes, that's what I meant. It's not that the Chinese will never be able to come up with models that superior --- it's simply that they will no longer have the incentive to open-source them once their models take the lead.

Training models are expensive. No one can do it for free for very long.