I severely doubt anything I do touches fortran millions times a day unless it's google search that runs on it.
At the end of the day Fortran is compiled and it can just create dynamic libraries which program you use depend on, and you'd never know.
Heck, I wouldn't bet against using me using at least 1 Cobol library once per month, you never know what kind of craziness is going on behind the scenes.
Banks have all kinds of random legacy crap written in all kinds of random languages. While COBOL is a lot more common, I guarantee you there are plenty of banks with bits of Fortran in their code bases. It is particularly found in older code for economic modelling, etc
Back in the old days, a lot of apps were written in Fortran that would never be written in that today. I used to work for a university where the application used to determine whether a student had met the graduation requirements for their degree was written in Fortran. Why Fortran? It was a manual process, then one of the professors offered to automate it for them, and he wrote the app in Fortran, because that was the language he was most comfortable with. And 30 years later they were still running it (although they finally replaced it with a COTS package when I worked there)
I once worked with an insurance company for whom a key business application was written in Turbo Pascal for DOS. They wrote it back in the 1980s when everyone had DOS machines. By the 2010s they were still running it in a VM. For all I know they are still doing that today
