What are the arguments to not use the yellow paper based International Certficate of Vaccination?
I just got a new one for 1.35 CHF and it's bug free.

WHO is also working on a digital version of this certificate https://www.who.int/ihr/ports_airports/icvp/en/

Their is a working group: https://www.who.int/groups/smart-vaccination-certificate-working-group
Why Swiss need their own version? Is is different from the WHO digital one? What are the specific features?
Their is a similar question in the EU parliament: https://www.europarl.europa.eu/doceo/document/P-9-2021-001802_EN.html
More generally about a digital passport, Mozilla nail it: "The question we need to ask ourselves is “is this vaccine passport system going to be empowering, or exclusionary?" https://foundation.mozilla.org/en/blog/digital-covid-vaccine-passports-five-key-takeaways/ . At a global scale, a digital only solution will definitely be exclusionary.