Work with informationsecurity and GDPR. And know as a fact that many danish municipalities which administrate the libraries are using, and are happy with, Linux as public facing citizen PC’s in libraries.
They use OS2borgerPC, which translates to OS2citizenPC which is maintained and supported by the danish company Magenta. But it’s open source, so if you are in another country you could just use it - or better, give Magenta a call. They’re great and very reseaonable.