I have heared about bankless card (basically, you can reload them at tabac/press shops). I am not sure how the service work in France, but there could be one similar in Belgium. Also, I am not sure how you would link that to your salary, social security things and other third parties.
Else you could try to look at how to create a minimal mutual/associative bank. I am sure it is a crazy thing to try and it requires even more than a lot of work, but it would be beautiful to make exist a bank which aim would only be to let people access their money (without profits, just a share of the costs).