The difference being that pre-pandemic we had 'targeted' vaccination i.e. if one is travelling to certain countries one had to have suitable vaccination cert. For example, for travel to (say) Africa or Asia, from Europe etc. one needed to have vaccination for yellow fever, polio etc. The effectiveness of these runs out after a few years, so one needed a booster for some. Since I travelled a lot, over decades, my certificate got to be quite lengthy.

Having said that, depending on your 'belief' system - if there was a pandemic or not recently, it makes sense from purely administrative pov to have this C19 vax on your certificate.

Whether WHO is corrupt or Gates makes money out of this doesn't enter into this equation per se.

The interesting part, for me, is how will WHO treat the legal status of C19 vaccines from different countries i.e. politics. Remember Russian vaccine Sputnik not being accepted by the west? Ditto China etc.

Check the small print ...