On large keyrings with a lot of X.509 certificates the validated key listing is not very fast. It scan's the keyrings far too often. With a certain 37 MiB keyring having about 1200 PGP and 900 X.509 certificates a

gpgsm --disable-dirmngr --with-validation -k >/dev/null

takes about 11 seconds on a i7-1370P and a fast NVME.