If I would like to print vector-tile based maps to pdfs for handout's or something, is there any CPU renderer, server- or client-side that could output SVGs instead of rasterizing on GPU to bitmap at some point?

I havent yet come across any renderer that would do this even partially, even before opening the whole can of worms that is text rendering.

Closest thing I'm aware of might be ArcGIS Maps for Adobe Creative Cloud but would need something that's more like a library and preferably FOSS.

Recent versions of QGIS support vector tiles in the MVT format (like these ones). So with a suitable style you should be able to create a layout using vector tiles and print.

Assuming you meet the relevant attribution/license requirements for the various bits you choose of course. I don't think any usage policy has been published for these tiles yet.

Unfortunately there are some translation issues with styles for MVT sources so you might need to do a bit of fixing if you don't want to go the route of a paid plan with MapTiler (third party provider) who have a plugin.

There's also a list of "print map" generators of varying types here: https://wiki.openstreetmap.org/wiki/OSM_on_Paper

QGIS can do this. It's a large dependency and loads Mapbox/Maplibre styles by converting them to internal ones, so it might look a little different than the standard Maplibre renderer, but you get the benefit of easily editing those styles.