"MRIs are actually widely available in most cities at reasonable cost" - I live in one of those first-world countries, and our citizens regularly wait many months if not over a year to get a single MRI scan. Yes, it's not just an issue of the MRI but the entire medical system, but the point still stands. Were there machines that were one or more orders of magnitude cheaper and simpler to run - I think we would see a marked increase in availability.
I agree on your ground-truth desire, and I would hope they've done a lot of that to validate what we see here.
Many months to a year for an MRI? Wow, in the USA, we can get MRI's the same day or at worst case, week. It's been that way for a decade or more.
I completely agree that's an issue, although more of an economic / public health policy issue than a technical one. There are low field MRI systems, such as the one made by Hyperfine that are, like you say, an order of magnitude cheaper and simpler to run. We should have these everywhere, IMO
https://www.hyperfinemri.com/