If it helps, I only have a high refresh phone display. I don't notice the difference when I'm using my slower displays because I'm not used to seeing those applications at a higher refresh rate. It doesn't seem to bother my mind.
I only notice it when I'm using another phone at a lower refresh rate.
The baseband firmware is not so privileged anymore. Most new phones, like the Google Pixel 7, have IOMMU to force the baseband to communicate through a very restricted interface to the kernel. Certainly, you can interfere with texts and calls, but a baseband RCE doesn't yet compromise the data stored on the phone by itself--not to diminish the seriousness or to suggest that we shouldn't patch such an exploit immediately.
RCE, the "remote" aspect, in the operating system? So directly in the kernel and accessible remotely, such as through the networking code? I'm curious now. Most of the ones I've seen are in some other component that is sandboxed. True system-level privilege RCEs seem to be relatively rare. Usually, you get RCE, then you need privilege escalation to do something especially interesting.
Indeed; I'm sometimes able to leverage even a few bits of memory corruption into execution in many cases, though the hardened allocator in Android makes this a serious PITA to arrange to overwrite something useful.