PyQGIS algorithm qgis:joinattributesbynearest not found

After re-installing Windows and QGIS 3.14 it seems like some PyQGIS algorithms are not working. For example:

processing.run("qgis:joinattributesbynearest", options)

gives

core.QgsProcessingException: Error: Algorithm qgis:joinattributesbynearest not found

I checked the algorithm ID in the latest docs, and it is correct.

For troubleshooting, I created a list of all available algorithms using

for alg in QgsApplication.processingRegistry().algorithms():
    print(alg.id(), "->", alg.displayName())

This results in quite a long file to share here but nowhere in the file I can find the algorithm name or identifier.

Note that the algorithm is available via the Processing Toolbox in the GUI, so I wonder where the PyQGIS version is hiding.