> opening a bank account but for claiming various other essential services, such as healthcare and education.

Where such services are provided by a functioning state maybe, but if they are, they also have a functioning currency and banking sector.

Where their isn't.... I had a Ukrainian friend who said in the worst days of state dysfunction (now decades ago), the de facto currency was bottles of vodka.

At least with a bottle of vodka, you can drown your sorrows if your currency crashes.... So your zeroth challenge is "How is Celo better and cheaper and more trustworthy than a bottle of vodka?