"Bancarización" is in the glossary as "banking", but askers don't always choose the best answer, and in this case "bank usage" would have been a better choice:
https://esl.proz.com/kudoz/spanish_to_english/finance_genera...

"Bancarización" is not simply banking per se; it means access to and use of banking services: how widely available they are and how much people use them. An accurate translation here would be "public use of and access to banking services". But that's a bit wordy, and I think a better alternative, particularly in a title would be "banking outreach" or "banking services outreach" (or perhaps "financial services outreach"). Economists use the word "outreach" here to mean availability and use. "Pública" doesn't need to be translated, because it's included in the idea of "outreach", which is inherently public. That's why it's difficult to find examples of "public banking (sector) outreach" online: because it's redundant.

"Bancarización
La bancarización es el grado y nivel de utilización que una población dentro de una economía hace de productos y servicios bancarios.
En el ámbito de la economía, el grado de bancarización expresa la intensidad e incidencia que la red bancaria tiene en la economía, y refleja además el grado de progreso del sistema financiero de un país."
http://economipedia.com/definiciones/bancarizacion.html

"Reaching out: Access to and use of banking services across countries
[...]
Banking sector outreach varies significantly across countries. In Ethiopia there is less than one branch per 100,000 people, while in Spain there are 96. In Albania, there are four loans per 1,000 people and the average loan size is 15 times GDP per capita, while in Poland there are 774 loans per 1,000 people and the average size ofloans is only one third of GDP per capita. This paper is a first attempt at measuring outreach and at investigating its determinants."
https://pure.uvt.nl/portal/files/1023776/Reaching_out_Access...