This is again will be very funny race to watch. Right now you can fairly do lots of reverse enginnering or "hacking" with off the shelf Chinese models, and they are very capable (GLM3 for example) which can be run locally if you stomach the hardware. Tools like rea are also becoming more popular. If openai continues to be pedantic, they will lose the technical base given how close is the gap getting.
For the past few days I've been trying to use rea to reverse engineer my Samsung Galaxy Buds 4 Pro to get seamless functionality working outside of the Samsung ecosystem with no luck (the buds 4 pro require Samsung devices + a Samsung account for seamless to work, I only have a Galaxy phone + my macbook). I think we're still far away from having something that works that well.
The company I work for has a plan B to switch to alternative, self-hosted models if providers pull off strange moves, such as drastic pricing changes. We have already switched from one provider to another once, and we do not want to get burned again. We do not reverse engineer, just regular development.