Mobile banking has been popular in the global south even before crypto boom exactly for the reason you mentioned. This has been a solved problem for a while and crypto bros would have realized it if they talked to a single person from Subsaharan Africa or South America in the past decade.

Also, people in the global south care about inflation because their staples becomes more expensive, not because their savings get eroded. Most of their assets are not liquid already. The rich ones have their money in dollar accounts and have access to the banking system. I don't think you actually understand how non-western world works in any of its aspects.